WO2016035415A1

WO2016035415A1 - Sputtering target

Info

Publication number: WO2016035415A1
Application number: PCT/JP2015/067226
Authority: WO
Inventors: 荒川　篤俊; 優斗森下
Original assignee: Ｊｘ金属株式会社
Priority date: 2014-09-04
Filing date: 2015-06-16
Publication date: 2016-03-10
Also published as: CN106029943B; MY179241A; CN106029943A; SG11201606737UA; JPWO2016035415A1; JP5946974B1

Abstract

Provided is a sputtering target containing: an alloy including Co or Fe as a main component; and an oxide including Mn and B. The sputtering target is characterized by having the composition, which satisfies the conditions of 9 at% ≦ Mn+B+O ≦ 56 at%, B ≦ Mn (at%), and Mn+B ≦ O (at%). This sputtering target is capable of suppressing abnormal discharge which is caused by a non-magnetic material and results in the formation of particles during sputtering.

Description

Sputtering target

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 or Fe, which is a ferromagnetic metal, is used for a recording layer of a hard disk adopting a perpendicular magnetic recording system. Of these, Co—Cr-based, Co—Pt, Co—Cr—Pt-based, and Fe—Pt-based alloys composed mainly of ferromagnetic metals and non-magnetic inorganic materials are often used. Yes. And the magnetic thin film of such magnetic recording media, such as a hard disk, is often produced by sputtering a sputtering target containing the above material as a component because of high productivity.

As a method for producing 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, but it cannot be unequivocally stated, but it is used for the recording layer of hard disks of the perpendicular magnetic recording system, an alloy mainly composed of a ferromagnetic metal and a non-magnetic inorganic substance. Sputtering targets made of particles are generally produced by powder metallurgy. 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.

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. A method has been proposed in which powder is formed by hot pressing to obtain a sputtering target for a magnetic recording medium.
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.

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 and has a low Proposals have been made to increase the film formation efficiency by obtaining a magnetic permeability and high density target.
Further, in Patent Document 4, the average particle diameter of the particles formed by the oxide phase is set to 3 μm or less, and in Patent Document 5, silica particles or titania particles are sputtered 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 of the target and Dp is a particle size in a direction parallel to the main surface.
In addition, in Patent Document 6, the average particle diameter of the oxide particles present in the target is 1.5 μm or less, and the maximum value of the distance between any two points on the outer periphery of the oxide particles is the maximum diameter, When the minimum value of the distance between two lines when the same particle is sandwiched between two parallel lines is set as the minimum diameter, oxide particles having a difference between the maximum diameter and the minimum diameter of 0.4 μm or less are observed on the target. It is described that it occupies 60% or more on the surface.
However, none of these conditions is sufficient and the present situation is that further improvement is required.

International Publication No. 2011/089760 Pamphlet JP 2009-1860 A JP 2009-102707 A JP 2009-215617 A JP 2011-2222086 International Publication No. 2013/125469 Pamphlet

Generally, in a non-magnetic material particle-dispersed sputtering target containing Co or Fe as a main component, an abnormal discharge is caused because a non-magnetic material such as an oxide is an insulator. Due to this abnormal discharge, generation of particles during sputtering becomes a problem. In particular, when B (boron) is contained, when a coarse oxide phase containing B is formed in the structure of the sputtering target, abnormal discharge occurs from that point and the number of particles increases significantly. there were.

As a result of intensive studies to solve the above problems, the inventors of the present invention have found that in a sputtering target containing an oxide phase as non-magnetic material particles, the oxide phase is formed in the form of a material having a high melting point. It has been found that by making it exist in the inside, the coarsening of the oxide phase can be prevented, an abnormal discharge due to a nonmagnetic material during sputtering does not occur, and a target with less generation of particles can be obtained.

Based on such knowledge, the present inventors provide the following inventions.
1) A sputtering target containing an alloy containing Co or Fe as a main component and an oxide containing Mn and B, and in the composition of the sputtering target, 9 at% ≦ Mn + B + O ≦ 56 at%, B ≦ Mn (at %) And Mn + B ≦ O (at%).
2) A sputtering target containing an alloy containing Co or Fe as a main component and Mn, B and X (where X is one or more elements selected from Co, Cr and Si), A sputtering target characterized in that the composition of the sputtering target satisfies the following conditions: 9 at% ≦ Mn + B + X + O ≦ 56 at%, B ≦ Mn + X (at%), Mn + X + B ≦ O (at%).
3) In the composition of the sputtering target, an oxide containing Mn and B or an oxide containing Mn, X and B is contained in an amount of 0.1 mol% or more and 15 mol% or less, respectively 1) or 2) The sputtering target as described.
4) On the surface or cross-sectional structure of the sputtering target, the maximum value of the distance between any two points on the outer periphery of the oxide particles is the maximum diameter, and the distance between the two lines when the particles are sandwiched between two parallel lines When the minimum value of the distance is the minimum diameter, the ratio of the maximum diameter to the minimum diameter shows a numerical value larger than 0.5, and oxide particles having a particle area of 6 μm ² or more are within 1 mm ² field of view. The sputtering target according to any one of 1) to 3) above, which has an average of 1 or less.
5) One or more elements selected from Pt, Ru, Ag, and Pd are contained in an alloy component of the sputtering target in an amount of 1 mol% to 50 mol%, according to any one of 1) to 4) above Sputtering target.

The non-magnetic material particle dispersion type magnetic material sputtering target of the present invention thus adjusted does not cause abnormal discharge due to the non-magnetic material during sputtering, and a target with less generation of particles can be obtained. Thereby, it has the outstanding effect that the cost improvement effect by a yield improvement can be acquired.

1 is a diagram (photograph) showing a cross-sectional structure of a sputtering target of Example 1. FIG. It is a figure (photograph) which shows the sputtering target cross-sectional structure of the comparative example 1.

The sputtering target of the present invention has a structure in which oxide particles containing Mn and B are dispersed as a nonmagnetic material in an alloy mainly composed of Co or Fe, which is a ferromagnetic metal. Examples of the alloy containing Co or Fe as a main component include ferromagnetic alloys such as a Co—Cr alloy, a Co—Pt alloy, a Co—Cr—Pt alloy, and an Fe—Pt alloy.
Oxide particles containing Mn and B contained as a nonmagnetic material have good wettability with an alloy containing Co or Fe as the main component, and are effective in improving the quality of the magnetic recording medium. However, when B ₂ O ₃ is included as an oxide, since the melting point is low, there is a problem that the oxide is dissolved during sintering and the oxide particles (phase) are coarsened. The present inventor can prevent the oxide agglomeration (coarse) in the sputtering target structure by forming the oxide containing B in the form of Mn—B—O and forming a material having a high melting point. It was possible to obtain the knowledge that the abnormal discharge caused by the aggregated portion of the oxide can be remarkably suppressed.

Based on the above knowledge, the sputtering target of the present invention is a sputtering target containing an alloy containing Co or Fe as a main component and an oxide containing Mn and B. In the composition of the sputtering target, 9 at% ≦ It is characterized by satisfying the conditions of Mn + B + O ≦ 56 at%, B ≦ Mn (at%), and Mn + B ≦ O (at%).
In the sputtering target, if the total content of Mn, B, and O is less than 9 at%, the effect of good characteristics of the perpendicular magnetic recording medium due to the inclusion of Mn, B, and O cannot be obtained, and Mn, B, and O When the total content of C exceeds 56 at%, the oxide phase itself composed of Mn—B—O becomes coarse. Further, when B> Mn (at%), B is not limited to the form of Mn—B—O, but B—O is present, and the B oxide is dissolved during the sintering, so that the oxide particles (Phase) becomes coarse. Further, when Mn + B> O (at%), the effect of good characteristics of the perpendicular magnetic recording medium cannot be obtained.

Regarding the oxide of B, in the case of containing X (where X is one or more elements selected from Co, Cr, Si) in addition to Mn, Mn—Co—B—O, Mn—Cr—B— By adopting forms such as O, Mn-Si-BO, Mn-Co-Cr-Si-BO, etc., the melting point is higher than that of B ₂ O _{3 and} the dissolution during sintering is suppressed. And abnormal discharge due to coarse particles during sputtering can be reduced.
In the composition of the sputtering target, the conditions of 9 at% ≦ Mn + X + B + O ≦ 56 at%, B ≦ Mn + X (at%), and Mn + X + B ≦ O (at%) are satisfied.
When the total content of Mn, X, B, and O is less than 9 at% in the composition of the sputtering target, the effect of good characteristics of the perpendicular magnetic recording medium due to the inclusion of Mn, X, B, and O cannot be obtained. When the total content of Mn, X, B, and O exceeds 56 at%, the oxide phase composed of Mn—X—B—O becomes coarse. In addition, when B> Mn + X (at%), B is not limited to the form of Mn—X—B—O, but B—O is present, and the B oxide is dissolved out during the sintering. The product particles (phase) become coarse. Further, when Mn + X + B> O (at%), the effect of good characteristics of the perpendicular magnetic recording medium cannot be obtained.

The present invention also covers the scope of the present invention in the case of a composition in which B is expressed as a simple substance instead of an oxide. For example, even when expressed as Co-40Pt-2B-2MnO-4CoO (mol%), B is not added as an oxide, but a reaction of 2B + 3CoO → B ₂ O ₃ + 3Co occurs during sintering. In some cases, a B oxide is formed, and the B oxide is melted during sintering and an enlarged structure is observed. In this case, Co-40Pt—B ₂ O ₃ -2MnO—CoO (mol%) is considered, and the composition of the Mn oxide, X oxide (corresponding to CoO) and B oxide in the sputtering target is set as described above. It is necessary to adjust to meet. Thus, even when B ₂ O ₃ is formed by oxidation, the composition of the sputtering target after oxidation is included in the scope of the present invention as long as the composition is within the range defined in the present invention.

The content of the above-described oxide containing Mn and B or the oxide containing Mn, X and B is preferably 0.1 mol% or more and 15 mol% or less in the composition of the sputtering target. If the amount is less than 0.1 mol%, the inclusion effect is hardly observed, and if it exceeds 15 mol%, the content is too large to obtain the desired effect. In the Mn—Si—B—O form, although the melting point is higher than that of B ₂ O ₃ , there is a composition range in which the melting point is low, so that adjacent particles are melted during sintering and become coarse. there's a possibility that. Therefore, the Si oxide content is preferably 10 mol% or less, and more preferably 6 mol% or less.

In the sputtering target of the present invention, the maximum value of the distance between any two points on the outer periphery of the oxide particle is set as the maximum diameter on the target surface or the cross-sectional structure, and the particle is sandwiched between two parallel straight lines. When the minimum value of the distance between two straight lines is the minimum diameter, the ratio of the maximum diameter to the minimum diameter is a value larger than 0.5, and the oxide particle having a particle area of 6 μm ² or more is 1 mm ^2. It is characterized by an average of less than 1 in the field of view. In addition, all the oxide particles in the sputtering target of the present invention do not show a numerical value in which the ratio of the maximum diameter to the minimum diameter is larger than 0.5.
When the particle area is 6 μm ² or more as a size that the B oxide is melted during sintering and the oxide phase becomes coarse, the increase in the number of particles is greatly affected.
If the shape of the oxide particles is long and continuous, it is difficult to cause grain breakage and discharge abnormalities, but the diameter of the oxide particles is close to a circle or square (that is, the ratio of the maximum diameter to the minimum diameter is 0.5). If it shows a larger numerical value), the increase in the number of particles has a great influence.
The observation of the structure of the sputtering target is performed at any five locations by polishing the target surface and using an electron microscope (viewing field: 1 mm ² ). The microscopic image is displayed on a PC screen, image analysis processing (binarization processing) is performed, the outline of the oxide particles (black portions) is clarified, and the number of oxide particles of a predetermined size is counted. The average number is obtained.

In the sputtering target of the present invention, as a magnetic metal, a Co alloy such as a Co—Cr alloy, a Co—Pt alloy, a Co—Cr—Pt alloy, or an Fe alloy such as an Fe—Pt alloy is effective. For example, a Co—Pt alloy composed of 1 mol% to 50 mol% of Pt, the balance Co and unavoidable impurities, Cr of 10 mol% to 50 mol%, Pt of more than 5 mol% and 50 mol% or less, the balance Co and A Co—Cr—Pt alloy composed of inevitable impurities, a Fe-based alloy composed of more than 1 mol% and not more than 50 mol%, the remaining Fe and inevitable impurities can be used. Furthermore, in order to improve the characteristics as a magnetic recording medium, it is preferable that one or more elements selected from Pt, Ru, Ag, and Pd are contained in an alloy component of the sputtering target in an amount of 1 mol% to 50 mol%. These are elements added as necessary, and the added amount is an effective amount for exerting the effect of addition.

The sputtering target of the present invention can be produced by a powder metallurgy method. In the case of powder metallurgy, a metal raw material powder such as Co, Fe, and Pt, a non-magnetic material raw material powder such as MnO, and an additive metal powder such as Ag are prepared as necessary. 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 meter.

What is important in the present invention is that an oxide raw material having a low melting point such as B oxide does not melt during sintering and the oxide phase is not coarsened. The oxides having a high melting point (MnBO ₃ , Mn ₃ B ₂ O ₆ or the like) is prepared in advance and used as a raw material powder. For MnBO ₃ powder, for example, mixing a _Mn 2 _{O 3} powder and _B 2 _{O 3} powder, synthetic, can be used after pulverizing. However, the MnBO ₃ powder may become Mn-rich, B-rich, and oxygen-rich MnBO ₃ powder rather than the stoichiometric ratio. In that case, it is preferable to analyze the Mn and B composition of the produced MnBO ₃ powder for each mixed, synthesized, and pulverized lot, and determine the weighed value so as to obtain a predetermined target composition. At that time, it is preferable to use a small amount of CoO powder, Mn powder, CoB powder or the like for adjustment to obtain a desired composition. The Mn ₃ B ₂ O ₆ powder, for example, can be used mixed with MnO powder and _B 2 _{O 3} powder, synthetic, those pulverized. However, since the Mn ₃ B ₂ O ₆ powder may be Mn-rich, B-rich, and oxygen-rich Mn ₃ B ₂ O ₆ powders rather than the stoichiometric ratio, as with the MnBO ₃ powder, it was prepared. It is preferable to analyze the Mn and B composition of the Mn ₃ B ₂ O ₆ powder for each lot that has been mixed, synthesized, and pulverized, and to determine the weighed value so as to obtain a predetermined target composition. At that time, it is preferable to use a small amount of CoO powder, Mn powder, CoB powder or the like for adjustment to obtain a desired composition. Next, these metal powders, non-magnetic material raw material powders, and the like 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.

The mixed powder obtained as described above is sintered using a hot press or a hot isostatic press. Although it depends on the component composition of the target, by setting the mixing conditions and sintering conditions for the above raw materials, the density is sufficiently high and the conditions for non-magnetic material particles to be finely dispersed in the metal phase are found. If the manufacturing conditions are fixed, a sintered body target in which such non-magnetic material particles are always dispersed can be obtained.

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.

(Example 1)
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, as a nonmagnetic material powder, Cr ₂ O ₃ powder with an average particle diameter of 1 μm, MnBO ₃ powder with an average particle diameter of 1.2 μm, A SiO ₂ powder having an average particle size of 0.7 μm and a CoO powder having an average particle size of 2 μm were prepared. For MnBO ₃ powder was used previously _Mn 2 _{O 3} _powder, B 2 _{O 3} powder mixed, synthetic, those pulverized. Then, 1500 g of these powders were weighed at the following composition ratio.
Composition (mol%): Co-20Pt-2B ₂ O ₃ -2CoO-2Cr ₂ O ₃ -4MnO-SiO ₂
The composition of the oxide component is as follows: Mn: 3.2 at%, X as Co: 1.6 at%, Cr: 3.2 at% and Si: 0.8 at%, B: 3.2 at%, O: 16 .1 at%.

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 in a carbon mold and hot-pressed in a vacuum atmosphere at a temperature of 980 ° 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 sputtering target having a diameter of 180 mm and a thickness of 4 mm.

As a result of polishing this target surface and observing arbitrary 5 points with an electron microscope, the ratio of the maximum diameter to the minimum diameter is larger than 0.5 within a 1 mm ² visual field, and the particle area is 6 μm. ^The average number of the ^two or more oxide particles was 0.5. In calculating the maximum diameter, the minimum diameter, and the particle area of the oxide particles, as shown in FIG. 1, a microscopic image is displayed on a PC screen, and image analysis processing (binarization processing) is performed. These were calculated after clarifying the outline of (black part).

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 seven. Even when sputtering is not performed, the number of particles on the silicon substrate may be counted as 4 to 6 when measured with a particle counter. Therefore, it can be said that the number of particles in this example is at an extremely low level. .

(Comparative Example 1)
As a metal raw material powder, a Co powder with an average particle size of 4 μm, a Pt powder with an average particle size of 3 μm, and as a nonmagnetic material powder, a Cr ₂ O ₃ powder with an average particle size of 1 μm, a B ₂ O ₃ powder with an average particle size of 2 μm, an average A MnO powder having a particle diameter of 1.2 μm and a SiO ₂ powder having an average particle diameter of 0.7 μm were prepared. Then, 1500 g of these powders were weighed at the following composition ratio.
Composition (mol%): Co-20Pt-5B ₂ O ₃ —Cr ₂ O ₃ -3MnO—SiO ₂
The composition of this oxide component is Mn: 2.3 at%, X is Cr: 1.6 at%, Si: 0.8 at%, B: 7.8 at%, O: 17.8 at%.

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 in a carbon mold, and in the same manner as in Example 1, sintered in a vacuum atmosphere by hot pressing at a temperature of 980 ° C., a holding time of 2 hours, and a pressure of 30 MPa. Got. Further, this was cut with a lathe to obtain a disk-shaped sputtering target having a diameter of 180 mm and a thickness of 4 mm.

As a result of polishing this target surface and observing arbitrary 5 points with an electron microscope, the ratio of the maximum diameter to the minimum diameter is larger than 0.5 in a 1 mm ² visual field, and the particle area is 6 μm ^2. The average number of the above oxide particles was 3.0. In calculating the maximum diameter, the minimum diameter, and the particle area of the oxide particles, the calculation was performed in the same manner as in Example 1.

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 35.

(Example 2)
As a metal raw material powder, Co powder with an average particle diameter of 4 μm, Pt powder with an average particle diameter of 3 μm, Ru powder with an average particle diameter of 5 μm, Mn powder with an average particle diameter of 4 μm, and CrBO _{3 with} an average particle diameter of 1 μm as a nonmagnetic material powder. A powder, MnBO ₃ powder having an average particle diameter of 1.2 μm, and TiO ₂ powder having an average particle diameter of 1 μm were prepared. For MnBO ₃ powder, pre-mixing the _Mn 2 _{O 3} powder and _B 2 _{O 3} powder, synthesized, it was used after grinding. The same was used for CrBO ₃ powder. At this time, a very small amount of Mn powder or Cr powder was used for adjusting the amount of oxygen associated with the use of MnBO ₃ powder or CrBO ₃ powder. Then, 1500 g of these powders were weighed at the following composition ratio.
Composition (mol%): Co-22Pt-5Ru-4B ₂ O ₃ -3Cr ₂ O ₃ -3MnO-TiO ₂
The composition of the oxide component is Mn: 2.3 at%, X is Cr: 4.5 at%, B: 6.0 at%, O: 19.6 at%. Note that Ti is omitted.

As a result of polishing this target surface and observing arbitrary 5 points with an electron microscope, the ratio of the maximum diameter to the minimum diameter is larger than 0.5 in a 1 mm ² visual field, and the particle area is 6 μm ^2. The average number of the above oxide particles was 0.8. In calculating the maximum diameter, the minimum diameter, and the particle area of the oxide particles, the calculation was performed in the same manner as in Example 1.

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 nine.

(Example 3)
As the metal raw material powder, Fe powder having an average particle diameter of 4 μm, Pt powder having an average particle diameter of 3 μm, Ag powder having an average particle diameter of 5 μm, and MnBO ₃ powder having an average particle diameter of 1.2 μm, an average particle diameter of 0 A 7 μm SiO ₂ powder was prepared. For MnBO ₃ powder was used previously _Mn 2 _{O 3} _powder, B 2 _{O 3} powder mixed, synthetic, those pulverized. Then, 1500 g of these powders were weighed at the following composition ratio.
Composition (mol%): Fe-42Pt-3Ag-B ₂ O ₃ -2MnO-7SiO ₂
The composition of the oxide component is Mn: 1.7 at%, X is Si: 5.8 at%, B: 1.7 at%, and O: 15.8 at%.

As a result of polishing this target surface and observing arbitrary 5 points with an electron microscope, the ratio of the maximum diameter to the minimum diameter is larger than 0.5 in a 1 mm ² visual field, and the particle area is 6 μm ^2. The average number of the above oxide particles was 1.0. In calculating the maximum diameter, the minimum diameter, and the particle area of the oxide particles, the calculation was performed in the same manner as in Example 1.

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 11.

Example 4
As the metal raw material powder, Co powder with an average particle size of 4 μm, Pt powder with an average particle size of 3 μm, Pd powder with an average particle size of 5 μm, and MnBO ₃ powder with an average particle size of 1.2 μm, an average particle size of 2 μm as a nonmagnetic material powder Co ₃ O ₄ powder was prepared. For MnBO ₃ powder, previously, _Mn 2 _{O 3} _powder, the B 2 _{O 3} powder mixed, synthesized, was used after grinding. Then, 1500 g of these powders were weighed at the following composition ratio.
Composition (mol%): Co-38Pt-2Pd-B ₂ O ₃ —Mn ₂ O ₃ -3Co ₃ O ₄
The composition of the oxide component is Mn: 1.6 at%, X is Co: 7.1 at%, B: 1.6 at%, and O: 14.3 at%.

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 eight.

(Example 5)
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, as nonmagnetic material powder, Mn ₃ B ₂ O ₆ powder with an average particle diameter of 2.4 μm, SiO ₂ powder with an average particle diameter of 2 μm A CoO powder having an average particle diameter of 2 μm was prepared. The Mn ₃ B ₂ O ₆ powder was used previously MnO _powder, B 2 _{O 3} powder mixed, synthetic, those pulverized. Then, 1500 g of these powders were weighed at the following composition ratio.
Composition (mol%): Co-15Pt-3MnO-1B ₂ O ₃ -2SiO ₂ -4CoO
The composition of this oxide component is Mn: 2.6 at%, X is Co: 3.5 at%, B: 1.7 at%, Si: 1.7 at%, O: 12.2 at%.

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 seven.

The present invention can suppress abnormal discharge due to a nonmagnetic material during sputtering by suppressing aggregation (coarseness) of the oxide phase. According to the present invention, the magnetic thin film of a magnetic recording medium, particularly a hard disk, has an excellent effect of reducing the generation of particles during sputtering caused by abnormal discharge and obtaining a cost improvement effect by improving yield. It is useful as a ferromagnetic material sputtering target used for forming a drive recording layer.

Claims

A sputtering target containing an alloy containing Co or Fe and an oxide containing Mn and B, wherein in the composition of the sputtering target, 9 at% ≦ Mn + B + O ≦ 56 at%, B ≦ Mn (at%), Mn + B ≦ A sputtering target characterized by satisfying the condition of O (at%).
A sputtering target comprising an alloy containing Co or Fe as a main component and an oxide containing Mn, B, and X (where X is one or more elements selected from Co, Cr, and Si), A sputtering target characterized by satisfying the following conditions in the composition of the sputtering target: 9 (at%) ≦ Mn + B + X + O ≦ 56 (at%), B ≦ Mn + X (at%), Mn + X + B ≦ O (at%).
3. The composition of the sputtering target, wherein the oxide containing Mn and B or the oxide containing Mn, X and B is 0.1 mol% or more and 15 mol% or less, respectively. Sputtering target.
On the surface or cross-sectional structure of the sputtering target, the maximum distance between any two points on the outer periphery of the oxide particle is the maximum diameter, and the distance between the two lines when the particles are sandwiched between two parallel lines When the minimum value is the minimum diameter, the ratio of the maximum diameter to the minimum diameter is a value larger than 0.5, and oxide particles having a particle area of 6 μm 2 or more are on average within 1 mm 2 field of view. The sputtering target according to any one of claims 1 to 3, wherein the number is one or less.
5. The sputtering target according to claim 1, wherein one or more elements selected from Pt, Ru, Ag, and Pd are contained in an alloy component of the sputtering target in an amount of 1 mol% to 50 mol%. .