KR100813140B1 - Perpendicular magnetic recording medium, its manufacturing method, recording method, and reproducing method - Google Patents

Abstract

The perpendicular magnetic recording medium has a structure in which a soft magnetic support layer, a seed layer, a magnetic flux slit layer, a nonmagnetic intermediate layer, a recording layer, a protective film, and a lubricating layer are sequentially stacked on the substrate, and the magnetic flux slit layer 13 It has soft magnetic particles having a substantially columnar structure having a boundary portion of the nonmagnetic portion, and the magnetic flux from the recording head is confined to only the portion of the soft magnetic particles to suppress the expansion of the magnetic flux. Also disclosed is a vertical magnetic recording medium provided with a magnetic flux slit layer on a recording layer.

Vertical magnetic recording media, soft magnetic, magnetic flux slit layer, recording layer, magnetic flux control layer

Description

Vertical magnetic recording medium, its manufacturing method, recording method and reproduction method {PERPENDICULAR MAGNETIC RECORDING MEDIUM, ITS MANUFACTURING METHOD, RECORDING METHOD, AND REPRODUCING METHOD}

The present invention relates to a vertical magnetic recording medium and a magnetic storage device, and more particularly, to a vertical magnetic recording medium and a magnetic storage device capable of high density recording.

Due to the rapid technological development of magnetic storage devices, in-plane recording methods for recording in the in-plane direction of a magnetic recording medium are making commercial devices with a surface recording density of 100 Gbit / square inch in the near future. However, the thermal stability of the recorded magnetization becomes a problem as the size of the recording unit is made smaller in the in-plane recording method with a boundary of 100 Gbit / square inch. In the future, it is possible to realize practical use up to 250Gbit / square inch by further improvement, but it is almost reaching the limit of surface recording density.

On the other hand, in the vertical recording method for recording in the vertical direction of the magnetic recording medium, since the thermal stability can be ensured by forming an appropriate thickness even if the size of the recording unit is made small, the surface recording density is tera (T) bits / square inch. It is expected to be possible to the generation.

In the vertical magnetic recording medium, a so-called two-layer vertical magnetic recording medium in which a soft magnetic support layer is provided between the recording layer and the substrate is the mainstream. The two-layer vertical magnetic recording medium has an effect of enhancing the recording magnetic field from the main magnetic pole of the recording head by the mirror image effect of the soft magnetic support layer, and increasing the inclination of the recording magnetic field by spatially concentrating the recording magnetic field.

However, since the soft magnetic support layer is disposed so as to face the main magnetic pole, the magnetic flux from the main magnetic pole is expanded toward the soft magnetic support layer and widens at the surface of the recording layer. There arises a problem that it cannot be formed, and high recording density cannot be achieved.

Further, as the high recording density increases, the medium noise increases along with the decrease in the reproduction output, so that the S / N improvement is being examined. Specifically, it is known that it is necessary to refine, isolate, orient, and improve the crystallinity of the magnetic particles of the recording layer. Although the magnetic particles of the recording layer are formed on the nonmagnetic intermediate layer, for example, the design of the nonmagnetic intermediate layer is important because the magnetic particles are affected by the crystal orientation and crystallinity of the nonmagnetic intermediate layer.

However, for example, if the film thickness is increased to improve the crystallinity and the like of the nonmagnetic intermediate layer, there is a problem that the crystallinity of the recording layer is improved, but the spacing from the recording head to the soft magnetic support layer is increased and the magnetic flux is widened. Occurs.

[Patent Document 1] Japanese Unexamined Patent Publication No. 2002-163819

[Patent Document 2] Japanese Patent Application Laid-Open No. 3-130904

[Patent Document 3] Japanese Unexamined Patent Publication No. 6-295431

[Patent Document 4] Japanese Patent Application Laid-Open No. 10-3644

[Patent Document 5] Japanese Patent Application Laid-Open No. 2001-134918

Accordingly, an object of the present invention is to provide a novel and useful vertical magnetic recording medium, a method of manufacturing the same, and a magnetic memory device which solve the above problems.

A more specific problem of the present invention is to provide a vertical magnetic recording medium capable of high density recording, which suppresses the expansion of the magnetic flux from the recording head, increases the recording magnetic field and sharply inclines the recording magnetic field.

Another more specific problem of the present invention is to provide a vertical magnetic recording medium capable of increasing S / N by increasing the miniaturization and isolation of crystal grains in a recording layer, and enabling high density recording.

According to a first aspect of the present invention, there is provided a vertical magnetic recording medium having a soft magnetic support layer and a recording layer provided on the soft magnetic support layer.

A vertical magnetic recording medium having a magnetic flux slit layer between the soft magnetic support layer and the recording layer, wherein the magnetic flux slit layer is a soft magnetic layer having a substantially columnar structure magnetically almost isolated in the in-plane direction. Is provided.

According to the present invention, since the magnetic flux slit layer provided between the soft magnetic support layer and the recording layer is a soft magnetic layer having a substantially columnar structure magnetically almost isolated in the in-plane direction, the magnetic flux at the recording head is in the in-plane direction within the magnetic flux slit layer. While the expansion to the surface is suppressed, the magnetic flux can be concentrated because the portion of the columnar structure is soft magnetic. Therefore, it is possible to increase the recording magnetic field in the recording layer and to sharply incline the recording magnetic field, thereby realizing a vertical magnetic recording medium capable of high density recording.

According to a second aspect of the present invention, there is provided a method of manufacturing a perpendicular magnetic recording medium having a soft magnetic support layer and a recording layer provided on the soft magnetic support layer.

And a step of forming the soft magnetic support layer, and a step of forming a recording layer, and between the step of forming the soft magnetic support layer and the step of forming the recording layer, Or a step of forming a magnetic flux slit layer made of a soft magnetic material at a higher atmospheric gas pressure.

According to the present invention, since the magnetic flux slit layer provided between the soft magnetic support layer and the recording layer is formed at the same or higher atmospheric gas pressure when the recording layer is formed, the atmospheric gas is absorbed into the soft magnetic material. Columnar structure is formed. Thus, a soft magnetic layer having a substantially columnar structure magnetically almost isolated in the in-plane direction is formed. Therefore, the magnetic flux from the recording head is suppressed in the in-plane direction in the magnetic flux slit layer, while the magnetic flux can be concentrated because the portion of the columnar structure is soft magnetic.

According to a third aspect of the present invention, there is provided a vertical magnetic recording medium having a soft magnetic support layer, a nonmagnetic intermediate layer provided on the soft magnetic support layer, and a recording layer provided on the nonmagnetic intermediate layer.

The nonmagnetic intermediate layer is made of nonmagnetic particles and a nonmagnetic first non-employment phase surrounding the nonmagnetic particles, and the recording layer is made of magnetic particles and a nonmagnetic second non-employment phase surrounding the magnetic particles. And the magnetic particles have a columnar structure and are epitaxially grown on the nonmagnetic particles to provide a perpendicular magnetic recording medium.

According to the present invention, a nonmagnetic intermediate layer provided under the recording layer is formed from the nonmagnetic particles and the first non-solid phase, and the nonmagnetic particles are arranged in a self-forming manner. In addition, since the magnetic particles of the recording layer are epitaxially grown on the nonmagnetic particles, the particle diameter of the magnetic particles and the spacing of neighboring magnetic particles can be controlled. Therefore, it is possible to realize miniaturization and isolation of magnetic particles at the same time, to reduce medium noise, to increase S / N, and to realize a vertical magnetic recording medium capable of high density recording.

Here, in the present specification, the epitaxial growth is substantially lattice matched with respect to the crystal plane in the growth direction of the film in the first layer which becomes the base layer and the second layer that grows thereon (the first layer of about 10% or less and the second layer). In addition to the case in which crystal growth is performed with respect to the first layer in a state where a lattice mismatch with a layer is obtained, and also in a direction perpendicular to the growth direction, that is, in-plane direction, there is a specific crystal orientation relationship, This also includes cases that do not have a specific crystal orientation relationship.

According to a fourth aspect of the present invention, there is provided a vertical magnetic recording medium having a soft magnetic support layer and a recording layer provided on the soft magnetic support layer.

Provided is a vertical magnetic recording medium having a soft magnetic shielding layer on the recording layer, wherein a recording magnetic field passes through a portion of the soft magnetic shielding layer which is magnetically saturated at a predetermined magnetic field to magnetize the recording layer. .

According to the present invention, a partial region of the soft magnetic shielding layer provided on the recording layer is formed as a magnetic saturation region by the recording magnetic field, and only the saturation region passes through, so that the recording layer below the saturation region is magnetized. Therefore, expansion of the magnetic flux from the recording head can be suppressed, and adjacent track erasure can be prevented. In addition, since the magnetic flux from the recording head is concentrated, the recording magnetic field can be increased and the writing performance of the recording layer can be improved.

According to a fifth aspect of the present invention, there is provided a vertical magnetic recording medium having a soft magnetic support layer and a recording layer provided on the soft magnetic support layer.

A magnetic flux slit layer is provided on the recording layer, wherein the magnetic flux slit layer is provided so that magnetic particles are arranged almost magnetically in the in-plane direction.

According to the present invention, since the magnetic flux slit layer is provided on the recording layer and the magnetic particles constituting the magnetic flux slit layer are arranged almost magnetically in the in-plane direction, the soft magnetic bearing is supported from the recording head through the magnetic flux slit layer and the recording layer. The magnetic flux circulating in the layer is constricted so as to pass the magnetic particles in the magnetic flux slit layer, so that the magnetic flux can be concentrated by suppressing the expansion of the magnetic flux from the recording head to the recording layer. Therefore, erasure of adjacent tracks due to expansion of magnetic flux can be prevented, and track density can be improved. Also, the width of the magnetization transition region can be narrowed in the length direction of the track, and the line recording density can be improved. As a result, a vertical magnetic recording medium of high recording density can be realized.

According to a sixth aspect of the present invention, there is provided a vertical magnetic recording medium having a soft magnetic support layer and a recording layer provided on the soft magnetic support layer.

A magnetic flux slit layer is provided on the recording layer, and the magnetic flux slit layer is provided with a vertical magnetic recording medium comprising a ferromagnetic mother phase made of a ferromagnetic material and nonmagnetic particles arranged in an in-plane direction.

According to the present invention, since the magnetic flux slit layer in which the nonmagnetic fine particles are arranged in the ferromagnetic matrix is provided on the recording layer, the magnetic flux circulating from the recording head to the soft magnetic support layer through the magnetic flux slit layer and the recording layer is the magnetic flux slit layer. Is constricted so as to pass through the ferromagnetic matrix between the nonmagnetic particles, and the magnetic flux can be concentrated by suppressing the expansion of the magnetic flux from the recording head to the recording layer. Therefore, erasure of adjacent tracks due to expansion of magnetic flux can be prevented, and track density can be improved. Also, the width of the magnetization transition region can be narrowed in the length direction of the track, and the line recording density can be improved. As a result, a vertical magnetic recording medium of high recording density can be realized.

According to a seventh aspect of the present invention, there is provided a magnetic storage device having any one of the above vertical magnetic recording media and recording / reproducing means.

According to the present invention, the perpendicular magnetic recording medium can raise the recording magnetic field in the recording layer at the same time as the magnetic flux from the recording head, while sharply inclining the recording magnetic field, and at the same time realize the miniaturization and isolation of the magnetic particles to increase the S / N. Therefore, a magnetic storage device of high density recording can be realized.

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1 is a schematic cross-sectional view of a vertical magnetic recording medium according to a first embodiment of the present invention.

2 is a schematic sectional view of a vertical magnetic recording medium according to a modification of the first embodiment;

3 is a schematic sectional view of a vertical magnetic recording medium according to a second modification of the first embodiment;

4 shows characteristics of the vertical magnetic recording medium according to Examples 1, 2 and Comparative Example 1. FIG.

Fig. 5 shows the S / Nm characteristics of the perpendicular magnetic recording medium according to Example 3 and Comparative Example 2. Figs.

6 is a schematic cross-sectional view of a vertical magnetic recording medium according to the second embodiment of the present invention.

7 (a) to 7 (c) are schematic views of a TEM photograph in plan view of the recording layer of the vertical magnetic recording medium according to Examples 4, 5 and Comparative Example 3, respectively.

Fig. 8 shows the characteristics of the vertical magnetic recording medium according to the embodiments 4 and 5;

Fig. 9 is a schematic sectional view of a vertical magnetic recording medium according to the third embodiment of the present invention.

Fig. 10 is a diagram showing the state of recording on the vertical magnetic recording medium according to the third embodiment.

FIG. 11 is a plan view of FIG. 10;

Fig. 12 is a diagram showing a reproduction form of the vertical magnetic recording medium according to the third embodiment.

FIG. 13 is a plan view of FIG. 12;

14 is a diagram schematically illustrating a film forming apparatus for applying a magnetic field to orient the easy magnetization axis.

FIG. 15 is a diagram schematically showing a film forming apparatus in which sputtered particles are inclined and incident to orient the easy magnetization axis. FIG.

Fig. 16 is a schematic cross sectional view of a vertical magnetic recording medium according to a modification of the third embodiment.

17 shows the relationship between S / Nm and the soft magnetic shielding layer film thickness of Example 6;

Fig. 18 is a graph showing the relationship between the regeneration output reduction rate of Example 6 and the soft magnetic shielding layer film thickness in the adjacent track erase test.

Fig. 19 shows the relationship between S / Nm and writing current of Example 6;

20 is a view showing a relationship between S / Nm and a nonmagnetic layer film thickness of Example 7;

Fig. 21 is a schematic sectional view of a vertical magnetic recording medium according to the fourth embodiment of the present invention.

Fig. 22 is a schematic sectional view of a vertical magnetic recording medium according to the fifth embodiment of the present invention.

Fig. 23 is a schematic sectional view of a vertical magnetic recording medium according to a modification of the fifth embodiment.

Fig. 24 is a schematic sectional view of a vertical magnetic recording medium according to the sixth embodiment of the present invention.

25 is a plan view of a vertical magnetic recording medium according to the sixth embodiment;

Fig. 26 is a plan view of a vertical magnetic recording medium according to a modification of the sixth embodiment.

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33 is a diagram showing main parts of a magnetic memory device of the ninth embodiment of the present invention;

34 is a schematic sectional view of a vertical magnetic recording head and a vertical magnetic recording medium.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail with reference to drawings as needed.

(1st embodiment)

First, the perpendicular magnetic recording medium according to the first embodiment of the present invention, wherein a magnetic flux slit layer of a substantially columnar structure made of a soft magnetic material is provided between the soft magnetic support layer and the recording layer.

1 is a schematic cross-sectional view of a vertical magnetic recording medium according to the first embodiment of the present invention. Referring to FIG. 1, the vertical magnetic recording medium 10 according to the present embodiment includes a substrate 11, a soft magnetic support layer 12, a seed layer 13, and a magnetic flux slit layer 14 on the substrate 11. And the nonmagnetic intermediate layer 15, the recording layer 16, the protective film 18, and the lubrication layer 19 are sequentially stacked.

The board | substrate 11 is comprised, for example from a crystallized glass board | substrate, a tempered glass board | substrate, a silicon board | substrate, an aluminum alloy board | substrate, etc., and when the perpendicular magnetic recording medium 10 is tape-shaped, it is polyester (PET) and polyethylene naphthalate. (PEN) and films, such as polyimide (PI) excellent in heat resistance, can be used.

The soft magnetic support layer 12 has a thickness of, for example, 50 nm to 2 μm, and includes at least one selected from Fe, Co, Ni, Al, Si, Ta, Ti, Zr, Hf, V, Nb, C, and B. It is composed of an amorphous or microcrystalline alloy containing an element or a laminated film of these alloys. In the point that the recording magnetic field can be concentrated, a soft magnetic material having a saturation magnetic flux density Bs of 1.0T or more is preferable. For example, FeSi, FeAlSi, FeTaC, CoNbZr, CoCrNb, NiFeNb, or the like can be used. The soft magnetic support layer 12 is formed by plating, sputtering, vapor deposition, CVD (chemical vapor deposition), or the like. The soft magnetic support layer 12 absorbs almost all of the magnetic flux from the recording head. In order to perform saturation recording, the higher the product of the saturation magnetic flux density Bs and the film thickness is, the better. In addition, the soft magnetic support layer 12 preferably has a higher high-frequency permeability in terms of writeability at a high transmission rate.

The seed layer 13 is 1.0 nm-10 nm in thickness, for example, and is selected from Ta, C, Mo, Ti, W, Re, Os, Hf, Mg, and these alloys. Increase the crystallinity of the magnetic flux slit layer 14 formed thereon, and disconnect the relationship between crystal orientation or crystal growth between the magnetic flux slit layer 14 and the soft magnetic support layer 12, and also disconnect the magnetic interaction. can do. In addition, the seed layer may or may not be provided.

The magnetic flux slit layer 14 is 0.5 nm-20 nm in thickness, for example, and is formed from the soft magnetic material. In the magnetic flux slit layer 14, the boundary between the soft magnetic particles of the soft magnetic material and the adjacent soft magnetic particles is composed of a low density body of the soft magnetic material. The soft magnetic particles extend perpendicularly to the membrane surface, one part grows from the seed layer under the ground, and the surface has a substantially columnar structure reaching the nonmagnetic intermediate layer 15. The boundary portion receives an inert gas such as He, Ne, Ar, Kr, or Xe into the soft magnetic material constituting the soft magnetic particles to form an amorphous state. Therefore, the boundary portion loses soft magnetic or the saturation magnetic flux density is smaller than that of the soft magnetic particles. The boundary portion may contain oxygen or nitrogen in addition to the inert gas, and oxygen or nitrogen may form a soft magnetic material and a compound.

The average particle diameter of the soft magnetic particles is preferably set to 3 nm to 10 nm (the diameter of the circle corresponding to the cross-sectional area of the soft magnetic particles in the cross section cut in the film surface direction) to 3 nm to 10 nm, and the adjacent soft magnetic particles. It is preferable that the average interval of is set to 0.5 nm to 3 nm.

The soft magnetic material used for the magnetic flux slit layer 14 is formed of a material containing at least any one selected from Co, Fe, Ni, Co-based alloys, Fe-based alloys, and Ni-based alloys as a main component. Moreover, you may further include any 1 type from the group which consists of Al, Ta, Ag, Cu, Pb, Si, B, Zr, Cr, Ru, Re, Nb, and C as an addition component. For example, an artificial lattice film of CoNbZr, CoZrTa, FeC, FeC, NiFe, FeTaC, FeCoAl, FeC film / C film is suitable as the soft magnetic material.

When the nonmagnetic intermediate layer 15 described later has an hcp structure, the magnetic flux slit layer 14 preferably has an hcp structure or an fcc structure, and the (001) plane of the hcp structure or the (111) plane of the fcc structure It is preferable to be an interface with a nonmagnetic intermediate layer. The magnetic flux slit layer 14 can be epitaxially grown, and crystallinity can be improved.

In addition, since the adjacent soft magnetic particles of the magnetic flux slit layer 14 are separated by the boundary portion, the crystal grains formed in the nonmagnetic intermediate layer 15 are similarly formed. As a result, the magnetic particles of the recording layer 16 formed on the nonmagnetic intermediate layer 15 are also separated and grown in the same manner, so that physical separation of the magnetic particles is promoted, and magnetic interaction of neighboring magnetic particles 20 is promoted. Can be reduced.

It is preferable that the magnetic anisotropy of the magnetic flux slit layer 14 has a larger in-plane magnetic anisotropy than the vertical magnetic anisotropy. When the perpendicular magnetic anisotropy is large, the noise increases due to the shaking of the magnetization component in the vertical direction with respect to the membrane surface during reproduction. In particular, the in-plane magnetic anisotropy magnetic field of the magnetic flux slit layer 14 is preferably greater than 711 kA / m.

The magnetic flux slit layer 14 is formed by a vacuum process such as sputtering or vacuum evaporation. Specifically, a predetermined film thickness is formed using a sputtering method, for example, a DC magnetron sputtering method, using an inert gas element such as He, Ne, Ar, Kr, or Xe or a mixed gas. It is preferable to set the vacuum degree at the time of film-forming to 1 Pa-8 Pa. At a pressure lower than 1 Pa, it is difficult to form a structure composed of soft magnetic particles and boundaries, and when it exceeds 8 Pa, the volume ratio of the soft magnetic particles becomes small, and magnetic flux cannot be sufficiently passed. Further, 2 Pa or more is preferable in view of more complete magnetic separation from neighboring soft magnetic particles, and 6 Pa or less in view of good epitaxial growth of the recording layer 16. Moreover, it is preferable to set the substrate temperature at the time of film-forming to 0 degreeC-150 degreeC (especially 15 degreeC-80 degreeC). In addition, from the point of promoting the formation of the boundary portion, nitrogen gas or oxygen gas may be mixed with the atmosphere gas in such a degree that the magnetic properties of the soft magnetic particles are not degraded.

The nonmagnetic intermediate layer 15 has a thickness of 2 nm to 30 nm, for example, and is composed of nonmagnetic materials such as Co, Cr, Ru, Re, Ri, Hf, and these alloys. The nonmagnetic intermediate layer 15 includes, for example, a Ru film, a RuCo film, a CoCr film, and the like, and preferably has a hcp structure. When the recording layer 16 has an hcp structure, it can be epitaxially grown and the crystallinity of the recording layer 16 can be improved.

The recording layer 16 is a so-called vertical magnetization film having an easy magnetization axis in the film thickness direction and is composed of a Co-based alloy containing CoCrTa, CoCrPt, and CoCrPt-M having a thickness of 3 nm to 30 nm. Here, M is selected from B, Mo, Nb, Ta, W, Cu and these alloys. Such a ferromagnetic alloy has a columnar structure, and in the case of the hcp structure, the film thickness direction, that is, the growth direction becomes the (001) plane, and has an easy magnetization axis in the film thickness direction. Examples of the recording layer 16 include CoCrPtB, CoCrPtTa, CoCrPtTaNb, and the like.

In addition, the recording layer 16 is a non-magnetic material composed of a compound of at least one element selected from Si, Al, Ta, Zr, Y, Mg, and at least one element selected from O, C, and N. It may further comprise a magnetic material, and may be composed of the crystal grains of the columnar structure of the ferromagnetic alloy described above and a nonmagnetic phase which physically separates adjacent crystal grains. Examples of the recording layer 16 include (CoPt)-(SiO ₂ ), (CoCrPt)-(SiO ₂ ), (CoCrPtB)-(MgO), and the like. Since the magnetic particles form a columnar structure and the nonmagnetic phase surrounds the magnetic particles, the magnetic particles can be separated from each other to effectively suppress or disconnect the interactions between the magnetic particles, thereby reducing the medium noise.

The recording layer 16 may be an artificial lattice film such as Co / Pd, CoB / Pd, Co / Pt, CoB / Pt. An artificial lattice film | membrane is comprised by laminating | stacking 5 to 30 layers, respectively alternately CoB (thickness: 0.3 nm) / Pd (thickness: 0.8 nm), for example. These artificial lattice films have excellent vertical magnetic anisotropy and are excellent in thermal stability.

The protective film 18 is formed by a sputtering method, a CVD method, a Filtered Cathodic Arc (FCA) method, or the like. For example, amorphous carbon, hydrogenated carbon, carbon nitride, aluminum oxide, or the like having a thickness of 0.5 nm to 15 nm is used. It is composed.

The lubrication layer 19 is applied by a pull up process, a spin coating method, or the like, and is composed of a lubricant having a thickness of 0.5 nm to 5 nm, and a main chain of a fluoropolyether. As the lubricant, for example, ZDol, Z25 (more than Monte Fluos), Z tetraor, AM3001 (more than Osmont) and the like can be used.

In a conventional vertical magnetic recording medium in which no magnetic flux slit layer is provided, the magnetic flux from the magnetic head spreads toward the soft magnetic support layer during recording, whereas in the vertical magnetic recording medium of the present embodiment, the magnetic flux slit layer ( (14) Since the soft magnetic particles having a substantially columnar structure and nonmagnetic boundaries are formed so that the magnetic flux passes only the soft magnetic particles having high magnetic permeability, the magnetic flux is confined to only the soft magnetic particles to suppress the expansion of the magnetic flux, and the recording layer 16 ) Can concentrate the magnetic flux. Therefore, the recording magnetic field can be made high and the spatial distribution of the recording magnetic field can be inclined, so that recording can be performed at a high recording density.

In the vertical magnetic recording medium of the present embodiment, since the soft magnetic particles of the magnetic flux seed layer are physically separated, the physical separation of the magnetic particles of the recording layer 16 formed through the nonmagnetic intermediate layer 15 is promoted. . As a result, magnetic interaction between neighboring magnetic particles can be reduced, and medium noise can be reduced.

2 is a schematic cross-sectional view of a vertical magnetic recording medium according to a first modification of the first embodiment. In the drawings, parts corresponding to the parts described above are denoted by the same reference numerals and description thereof will be omitted.

Referring to FIG. 2, the vertical magnetic recording medium 30 includes a substrate 11, a soft magnetic support layer 12, a seed layer 13, an underlayer 31, and a magnetic flux slit layer 14 on the substrate 11. ), The nonmagnetic intermediate layer 15, the recording layer 16, the protective film 18, and the lubrication layer 19 are laminated in this order. The vertical magnetic recording medium 30 according to the present modification is characterized in that an underlayer 31 is further provided between the seed layer 13 and the magnetic flux slit layer 14.

The base layer 31 has a thickness of, for example, 0.5 nm to 20 nm, and has a soft magnetic material mainly composed of at least one selected from Co, Fe, Ni, Co-based alloys, Fe-based alloys, and Ni-based alloys. It consists of. Moreover, you may further contain any 1 type of group which consists of Mo, Cr, Cu, V, Nb, Al, Si, B, C, and Zr as an addition component. By functioning as a growth nucleus of the magnetic flux slit layer 14, the crystallinity of the soft magnetic particles of the magnetic flux slit layer 14 can be improved and the isolation can be promoted. In addition, by having soft magnetic properties, spacing between recording head soft magnetic support layers can be reduced. The base layer 31 is formed by a vacuum process such as a sputtering method or a vacuum deposition method, for example, and has an atmospheric gas pressure lower than the atmospheric gas pressure when the magnetic flux slit layer 14 is formed, for example, 2 Pa or less. It is preferable to set. Good growth nuclei or initial growth layers can be formed.

According to this modification, since the crystallinity of the soft magnetic particles of the magnetic flux slit layer 14 is improved, the crystallinity of the magnetic particles of the recording layer 16 formed through the nonmagnetic intermediate layer 15 can be further improved. . As a result, the anisotropic magnetic field of the recording layer 16 can be improved and the coercive force can be improved.

3 is a schematic sectional view of a vertical magnetic recording medium according to a second modification of the first embodiment. In the drawings, parts corresponding to the parts described above are denoted by the same reference numerals and description thereof will be omitted.

Referring to FIG. 3, the perpendicular magnetic recording medium 35 includes a substrate 11, a soft magnetic support layer 12, a magnetic flux slit layer 36, a seed layer 13, and a nonmagnetic intermediate layer on the substrate 11. 15), the recording layer 16, the protective film 18, and the lubrication layer 19 are laminated | stacked sequentially. The vertical magnetic recording medium 35 according to the present modification is characterized in that the magnetic flux slit layer 36 is provided in contact with the magnetic support layer 12.

The magnetic flux slit layer 36 is substantially the same as the magnetic flux slit layer 14 shown in FIG. The magnetic flux slit layer 36 is preferably set to a thickness of 0.3 nm to 10 nm, and the in-plane anisotropy of the magnetic flux slit layer 36 is set equal to or greater than the in-plane anisotropy of the soft magnetic support layer 12. It is preferable. In-plane anisotropy can be improved by thinning the magnetic flux slit layer 36, and noise caused by the soft magnetic support layer 12 such as spike noise can be suppressed. In addition, since the magnetic flux slit layer 36 is in contact with the soft magnetic support layer 12, the expansion of the magnetic flux on the surface of the soft magnetic support layer 12 can be effectively suppressed, and the magnetic flux in the recording layer 16 is narrowed. The effect can be further enhanced.

In addition, since the magnetic flux slit layer 36 has greater in-plane magnetic anisotropy than the vertical anisotropy, the spike noise caused by the magnetization of the soft magnetic support layer 12 shaking in the direction perpendicular to the plane during reproduction can be further reduced.

In the vertical magnetic recording medium of this modification, in addition to the effect of the vertical magnetic recording medium according to the first embodiment, as described above, the magnetic flux narrowing effect at the time of recording is further enhanced, and the soft magnetic backing layer 12 is caused. Noise can be reduced.

Further, the perpendicular magnetic recording medium of the first embodiment or the first modification and the second modification may be combined.

Hereinafter, the Example which concerns on this embodiment, and the comparative example which does not depend on this invention are shown.

Example 1

The perpendicular magnetic recording medium according to the present embodiment was configured as shown below. From the substrate side, the glass substrate / soft magnetic support layer: CoNbZr film (180 nm) / seed layer: Ta film (5 nm) / magnetic flux slit layer: NiFe film (5 nm) / nonmagnetic intermediate layer: Ru film (Xnm) / recording layer: (Co ₇₆ Cr ₉ Pt ₁₅ ) 90 vol%-(SiO ₂ ) 10 vol% film (10 nm) / protective film: carbon film (4 nm) / lubrication layer: AM3001 film (1.5 nm). Except for the lubricating layer, it was formed using a sputtering apparatus in an Ar gas atmosphere, and the atmospheric gas pressure at the time of film formation of the CoNbZr film and the Ta film was 0.5 Pa, and the atmospheric gas pressure of the NiFe film and the Ru film was 4.0 Pa. In addition, the numerical value in the said parenthesis shows a film thickness, and the film thickness X of Ru film produced the sample different from X = 7, 10, 15, and 20 nm.

Example 2

Example 1 except that the base layer: NiFe film (5 nm) was formed between the seed layer of Example 1 by Ta film (5 nm) and the magnetic flux slit layer: NiFe film (5 nm) by setting the atmospheric gas pressure to 0.5 Pa. Same as

Comparative Example 1

Magnetic flux slit layer of Example 1: It is the same as that of Example 1 except the NiFe film (5 nm) formed by setting the atmospheric gas pressure to 0.5 Pa.

4 is a diagram showing the characteristics of the vertical magnetic recording medium according to Examples 1, 2, and Comparative Example 1. FIG. Α in the figure shows the inclination 4π × ΔM / ΔH near the coercive force of the magnetization curve measured by applying a magnetic field in the vertical direction with respect to the recording layer, and indicates that magnetic isolation of the magnetic particles proceeds as α approaches 1.

Referring to Fig. 4, in Comparative Examples 1 to 4.1 and 4.9, in Examples 1 and 2, it is 1.7 to 3.1. Therefore, Examples 1 and 2 know that magnetic particles are isolated.

Regarding the standard coercive force, the comparative examples 1 are 0.23 to 0.31, while in Examples 1 and 2, they are greatly increased to 0.33 to 0.45. Since the normalized coercive force indicates that the magnetic interaction between the magnetic particles is smaller, the magnetic interactions of Examples 1 and 2 are smaller than that of Comparative Example 1. As a result, Example 1 and 2 were significantly reduced with respect to the comparative example 1, and it turns out that S / Nm improves. In addition, although not shown in the drawing, cross-sectional TEM observation of the perpendicular magnetic recording medium of Example 2 shows that in the Ru film on the NiFe film of the magnetic flux slit layer, crystal particles of substantially columnar structure are formed, and the magnetic particles of the recording layer are independently It was confirmed that it was formed.

When Example 1 is compared with Example 2, Example 2 is larger than Example 1 regarding S / Nm. In Example 2, since the NiFe film (film thickness of 5 nm) formed by setting the atmospheric gas pressure to 0.5 Pa was formed in Example 1, the NiFe film (atmosphere gas pressure: 4.0 Pa, as a magnetic flux slit layer formed thereon) was formed. It is considered that the crystallinity of the film thickness of 5 nm) is improved, and the crystallinity of the recording layer magnetic particles is improved by the excellent crystallinity effect.

In addition, coercive force (Hc) and anisotropic magnetic field (Hk) were measured using VSM. In addition, the medium noise and S / Nm were measured using a complex magnetic head (recording head: terminal pole head, light core width 0.5 μm, reproduction head (GMR element): lead core width 0.25 μm) having a floating amount of 17 nm. The recording density was 400 kFCI.

Example 3

As a vertical magnetic recording medium according to the present embodiment, a vertical magnetic recording medium having the following constitution is produced. Glass substrate / soft magnetic support layer from the substrate side: CoNbZr film (190 nm) / magnetic flux slit layer: CoNbZr film (10 nm) / seed layer: Ta film (2 nm) / nonmagnetic intermediate layer: Ru film (15 nm) / recording layer: ( Co ₇₁ Cr ₉ Pt ₂₀ ) 90 vol%-(SiO ₂ ) 10 vol% film (10 nm) / protective film: carbon (4 nm) / lubrication layer: AM3001 (1.5 nm). Except for the lubricating layer, it was formed using a sputtering apparatus in an Ar gas atmosphere, and the atmospheric gas pressure of the CoNbZr film and the Ta film of the soft magnetic support layer was 0.5 Pa, and the atmospheric gas pressure of the CoNbZr film and the Ru film of the magnetic flux slit layer was 4.0 Pa. .

Comparative Example 1

It is the same as Example 1 except having formed the CoNbZr film | membrane of the magnetic flux slit layer of Example 3 by setting atmospheric gas pressure to 0.5 Pa.

5 is a diagram showing S / Nm characteristics of the vertical magnetic recording medium according to Example 3 and Comparative Example 2. FIG. Referring to Fig. 5, it is understood that Example 3 is larger in S / Nm than Comparative Example 2 at a recording density of 200 kFCI or more. For example, at 400 kFCI, Example 3 is increased by 1.7 dB compared to Comparative Example 2. By forming the CoNbZr film of the magnetic flux slit layer at an atmospheric gas pressure of 4.0 Pa, magnetic isolation is promoted than that of the CoNbZr film formed at 0.5 Pa of Comparative Example 2, and the expansion of the magnetic flux from the recording head is suppressed and the medium noise is reduced. I think. In addition, S / Nm characteristic is the same as the measurement conditions mentioned above.

(2nd embodiment)

A perpendicular magnetic recording medium according to a second embodiment of the present invention, in which nonmagnetic particles and magnetic particles of a nonmagnetic intermediate layer and a recording layer are surrounded by a non-employed phase and separated from each other, will be described.

6 is a schematic cross-sectional view of a vertical magnetic recording medium according to the second embodiment of the present invention. In the drawings, parts corresponding to the parts described above are denoted by the same reference numerals and description thereof will be omitted.

Referring to FIG. 6, the vertical magnetic recording medium 40 includes a substrate 11, a soft magnetic support layer 12, a seed layer 13, an underlayer 31, and a nonmagnetic intermediate layer 41 on the substrate 11. ), The recording layer 42, the protective film 18, and the lubrication layer 19 are laminated in this order.

The recording layer 42 is made of a nonmagnetic material that physically isolates the magnetic particles 42a having a columnar structure at a thickness of, for example, 6 nm to 20 nm and the adjacent magnetic particles 42a surrounding the magnetic particles 42a. It consists of the 2nd non-employment phase 42b which consisted of. The columnar structure of the magnetic particles 42a extends in the film thickness direction, and is formed so as to fill the second non-solid phase 42b between each of the plurality of magnetic particles 42a arranged in the in-plane direction.

The magnetic particles 42a are made of any one material of the group consisting of Ni, Fe, Co, Ni-based alloys, Fe-based alloys, Co-based alloys including CoCrTa, CoCrPt, and CoCrPt-M. Where M is selected from B, Mo, Nb, Ta, W, Cu and these alloys. When the magnetic particles 42a have an easy magnetization axis in the film thickness direction, and the ferromagnetic alloy constituting the magnetic particles 42a has a hcp structure, the film thickness direction, that is, the growth direction is preferably the (001) plane.

When the magnetic particles 42a are made of a CoCrPt alloy, the Co content is set to 50 atomic% to 80 atomic%, the Cr content to 5 atomic% to 20 atomic%, and the Pt content is set to 15 atomic% to 30 atomic%. By containing much Pt content compared with the conventional magnetic recording medium, a perpendicular anisotropic magnetic field can be increased and high coercive magnetization can be attained. In particular, such high Pt content has been difficult to epitaxially grow with respect to the Cr-based base material, but magnetic particles 42a having excellent crystallinity can be formed by using the material of the nonmagnetic particles 42a of this embodiment.

The second non-solid phase 42b is composed of a ferromagnetic alloy forming the magnetic particles 42a and a nonmagnetic material which does not form a solid solution or a compound. The nonmagnetic materials are Si, Al, Ta, Zr, Y, Ti, and It consists of a compound of any one element selected from Mg, and at least any one element selected from O, N, and C. For example, SiO ₂ , Al ₂ O ₃ , Ta ₂ O ₅ , Oxides such as ZrO ₂ , Y ₂ O ₃ , TiO ₂ , Mg, nitrides such as Si ₃ N ₄ , AlN, TaN, ZrN, TiN, Mg ₃ N ₂ , and carbides such as SiC, TaC, ZrC, TiC Can be mentioned. Since the magnetic particles 42a are physically isolated from the neighboring magnetic particles 542a by the second non-solid phase 42b made of such a nonmagnetic material, magnetic interaction is reduced, and as a result, medium noise can be reduced. Can be.

The nonmagnetic material constituting the second non-solid phase 42b is preferably an insulating material. The interaction between the magnetic particles 42a due to the tunnel effect of electrons responsible for ferromagneticity can be reduced.

The volume concentration of the second non-employed phase 42b is preferably set in the range of 2 vol% to 40 vol% based on the volume of the recording layer 42. If it is out of 2 vol%, the magnetic particles 42a cannot be sufficiently separated, so that the magnetic particles 42a cannot be isolated sufficiently, and if it exceeds 40 vol%, the saturation magnetization of the recording layer 42 is markedly lowered. This degrades. The volume concentration of the second non-solid phase 42b is particularly preferably set in the range of 8 vol% to 30 vol% in terms of isolation of the magnetic particles 42a and dispersion of the vertical alignment.

The nonmagnetic intermediate layer 41 has a thickness of 3 nm to 40 nm, for example, and is not dissolved in solid solution with crystalline nonmagnetic particles 41a made of a nonmagnetic material, and the nonmagnetic particles 41a surrounding the nonmagnetic particles 41a. It consists of the first non-employed phase 41b made of a non-material.

The nonmagnetic particles 41a are made of Co, Cr, Ru, Re, Ti, Hf, and at least one nonmagnetic material selected from these alloys having an hcp structure or an fcc structure, for example Ru or CoCrRu. Can be. It is preferable that the (001) plane is the case where the nonmagnetic particles 41a have the hcp structure and the (111) plane is substantially parallel to the in-plane direction when the fcc structure is used. At the interface between the nonmagnetic intermediate layer 41 and the recording layer 42, the magnetic particles 42a can be epitaxially grown on the nonmagnetic particles 41a, and the particle diameters of the nonmagnetic particles 41a and neighboring nonmagnetic By controlling the interval with the particles 41a, the particle diameter of the magnetic particles 42a and the interval between the adjacent magnetic particles 42a can be controlled at the same time.

In addition, the 1st non-solid phase 41b is comprised from the same material as the 2nd non-solid phase 42b mentioned above. The volume concentration of the first non-employed phase 41b is preferably set in the range of 2 vol% to 40 vol% based on the volume of the nonmagnetic intermediate layer 41. Further, the volume concentration of the first non-employed phase 41b is particularly preferably equal to or larger than the volume concentration of the second non-employed phase 42b, and the volume concentration of the first non-employed phase 41b: the second non-employed phase 42b. It is particularly preferable to have a volume concentration of 1: 1: 1 to 1.5: 1. The magnetic particles 42a tend to grow on the nonmagnetic particles 41a and thus have a large particle size, so that the volume concentration of the first non-solid phase 41b is equal to or larger than the volume concentration of the second non-solid phase 42b. Isolation of the magnetic particles 42a can be achieved.

It is preferable to control the particle size of the nonmagnetic particles 41a by the base layer 31 formed below the nonmagnetic intermediate layer 41. The base layer 31 is comprised from the material of the base layer 31 demonstrated by 1st Embodiment. By the underlying layer 31 functioning as a growth nucleus of the nonmagnetic particles 41a, the arrangement of the nonmagnetic particles 41a can be controlled, and the crystal orientation and crystallinity can be improved.

It is preferable that the material of the base layer 31 has an fcc structure, and the (111) plane is substantially parallel to the substrate plane, and the ratio of lattice mismatch with the nonmagnetic particles 41a is 10% or less. That is, crystallographically, the underlayer 31: fcc structure (111) plane // nonmagnetic intermediate layer 41: fcc structure (111) plane or hcp structure (001), and the ratio of lattice mismatch is 10% or less. It is preferable.

In addition, since the underlayer 31 is formed of a soft magnetic material, the underlayer 31 functions as a part of the soft magnetic support layer 12, thereby reducing the spacing from the magnetic head to the soft magnetic support layer 12 surface. It is possible to improve the electron conversion characteristics. In addition, the base layer 31 may or may not be provided.

In the vertical magnetic recording medium 40 of this embodiment, a seed layer is provided below the base layer 31. It has the function described in the first embodiment. In addition, the base layer 31 may or may not be provided.

Hereinafter, a method of forming the nonmagnetic intermediate layer 41 and the recording layer 42 will be described.

The nonmagnetic intermediate layer 41 and the recording layer 42 are formed using a sputtering method, for example, a DC magnetron sputtering apparatus, an ECR sputtering apparatus, or the like, and an RF magnetron sputtering apparatus or the like in the case of containing an insulating material.

When the nonmagnetic intermediate layer 41 is formed, the sputtering target of the nonmagnetic material composed of the nonmagnetic particles 41a and the sputtering target of the material composed of the first non-solid phase 41b may be sputtered at the same time. A material obtained by combining a nonmagnetic material composed of 41a) and a material composed of the first non-employed phase 41b may be used. In the case of forming the recording layer 42, a sputtering target is used for each of the magnetic material of the magnetic particles 42a and the nonmagnetic material of the second non-employment phase 42b, as in the case of the nonmagnetic intermediate layer 41. You may use the compounded thing.

It is preferable to set the atmospheric gas pressure at the time of film-forming in the range of 2Pa-8Pa. Isolation of the nonmagnetic particles 41a or the magnetic particles 42a can be promoted. In addition, it is preferable to use Ar gas or Ar gas which added oxygen gas as an atmospheric gas.

According to this embodiment, the nonmagnetic intermediate layer 41 provided below the recording layer 42 is formed of the nonmagnetic particles 41a and the first non-solid phase 41b so that the nonmagnetic particles 41a are self-forming. And the magnetic particles 42a of the recording layer 42 grow from the surface of the nonmagnetic particles 41a, so that the particle diameter of the magnetic particles 42a and the interval between adjacent magnetic particles 42a are adjusted. Can be controlled. Therefore, miniaturization and isolation of the magnetic particles 42a can be realized simultaneously.

Example 4

The perpendicular magnetic recording medium according to the present embodiment was configured as shown below. From the substrate side, glass substrate / soft magnetic support layer: CoNbZr film (120 nm) / seed layer: Ta film (5 nm) / base layer: NiFe film (5 nm) / nonmagnetic intermediate layer: Ru ₈₆ vol%-(SiO ₂ ) 14 vol% Film (20 nm) / recording layer: (Co ₇₆ Cr ₉ Pt ₁₅ ) 76 vol%-(SiO ₂ ) 24 vol% film (10 nm) / protective film: carbon film (4 nm) / lubrication layer: AM3001 (1.5 nm). It formed using the sputtering apparatus of Ar gas atmosphere, and formed the CoNbZr film | membrane, Ta film | membrane, NiFe film | membrane, and carbon film by setting Ar atmosphere gas and pressure to 0.5 Pa using DC magnetron sputtering apparatus. In addition, the nonmagnetic intermediate layer and the recording layer used an RF magnetron sputtering apparatus, and the Ar atmosphere gas and gas pressure were 4.0 Pa. The substrate temperature at the time of film formation was room temperature. The lubricating layer was applied by the dipping method. In addition, the numerical value in the said parenthesis shows a film thickness.

Example 5

Embodiment, instead of the non-magnetic intermediate layer in Example 4, ₆₀ vol% Ru - same as (SiO ₂₎ except that the film formed using the 35vol% (20nm), Example 4.

Comparative Example 3

It is the same as Example 4 except having used Ru film (20 nm) instead of the nonmagnetic intermediate | middle layer of Example 4.

7 (a) to 7 (c) are schematic views of a TEM photograph in plan view of the recording layer of the vertical magnetic recording medium according to Examples 4, 5 and Comparative Example 3, respectively. In the figure, the curve shows the outline of the magnetic particles 42a and 42a-1.

7 (a) to 7 (c), the recording layer of the vertical magnetic recording medium according to the fourth and fifth embodiments shown in FIGS. 7A and 7B is shown in FIG. It is understood that the isolation and refinement of the magnetic particles 42a are promoted as compared with Comparative Example 3 in which the Ru film shown in (c) is used for the nonmagnetic intermediate layer. The average particle diameter of the magnetic particles was Example 4: 5.6 nm, Example 5: 5.5 nm, and Comparative Example 3: 7.7 nm.

In particular, Example 5, there is a growing gap than that of the magnetic particle to the neighboring (42a), i.e. the distance between the second note magnetic particles (42a) sandwiching a portion of the jerk (42b) made of SiO _2. Example 4 In addition, with respect to the non-solid-phase 42b-1 shown to FIG. 7C, in Example 5, it turns out that the 2nd non-solid-phase 42b surrounds the magnetic particle 42a uniformly. It is known that the volume of the magnetic particles in the recording layer increases by increasing the volume concentration of the first non-employed phase of the nonmagnetic intermediate layer from 14 vol% to 35 vol% and higher than the volume concentration of 24 vol%, which is the second non-employed phase of the magnetic layer.

8 is a diagram showing the characteristics of the vertical magnetic recording medium according to the fourth and fifth embodiments. Referring to FIG. 8, the fifth embodiment is closer to one than the fourth embodiment with respect to α. (alpha) shows that magnetic isolation of a magnetic particle is progressing as close to 1 as mentioned above, and Example 5 knows that magnetic isolation is progressing rather than Example 4. FIG. It is also understood that this coincides with the physical isolation of the planar TEM photograph described above.

With respect to S / Nm, while Example 4 is 11 dB, Example 5 is significantly improved to 18 dB. Consistent with the result of α, the isolation of the magnetic particles is promoted, and the media noise is reduced and the S / Nm is improved.

Similarly, in D50, the fifth embodiment is larger than the fourth embodiment. It is seen from this that a higher density recording is possible.

Therefore, according to this embodiment, by making the nonmagnetic intermediate layer a Ru- (SiO ₂ ) film, the magnetic particles can be isolated and refined as compared with the Ru film. In addition, the distance between the magnetic particles can be controlled by the volume concentration of the first non-solid phase of the nonmagnetic intermediate layer, and magnetic isolation of the magnetic particles is possible. Further, by making the volume concentration of the first non-solid phase of the nonmagnetic intermediate layer higher than the volume concentration of the second non-solid phase of the recording layer, it is possible to further isolate the magnetic particles and improve the S / Nm and D50.

Further, although not shown in the drawing, the cross-sectional TEM observation of the vertical magnetic recording media of Examples 4 and 5 shows that the non-magnetic particles and the magnetic particles extend in the film thickness direction in the nonmagnetic intermediate layer 41 and the recording layer 42. We confirmed that we had structure.

In addition, the measuring method of average particle diameter extracts the outline of the magnetic particle of a planar TEM photograph (2 million times in a photograph), inputs it into a PC with a scanner, and obtains the area of a magnetic particle, and calculates the diameter of the circle corresponding to the area of a magnetic particle 150 magnetic particles were randomly selected as the particle size, and the average value of those particle diameters was obtained to obtain an average particle diameter.

Vertical coercive force, saturation magnetization, and α were measured under the same conditions as in Examples 1 and 2 according to the first embodiment. In addition, S / Nm and D50 were measured using the complex magnetic head (recording head: terminal pole head, light core width 0.5 micrometer, regeneration head (GMR element): 0.25 micrometer width) of floating amount 17 nm.

(Third embodiment)

A vertical magnetic recording medium according to a third embodiment of the present invention in which a soft magnetic shielding layer is provided on a recording layer will be described.

9 is a schematic cross-sectional view of a vertical magnetic recording medium according to the third embodiment of the present invention. In the drawings, parts corresponding to the above-described parts are denoted by the same reference numerals, and description thereof is omitted.

Referring to FIG. 9, the vertical magnetic recording medium 50 includes a substrate 11, a soft magnetic support layer 12, a seed layer 13, an underlayer 31, and a nonmagnetic intermediate layer 15 on the substrate 11. ), The recording layer 16, the soft magnetic shielding layer 51, the protective film 18, and the lubrication layer 19 are laminated in this order.

The soft magnetic shielding layer 51 is formed on the recording layer 16 described in the first or second embodiment, and is made of, for example, a soft magnetic material having a high permeability of 2 to 50 nm in thickness. The soft magnetic material used for the soft magnetic shielding layer 51 includes at least one element selected from Fe, Co, Ni, Al, Si, Ta, Ti, Zr, Hf, V, Nb, C, and B. Amorphous or microcrystalline alloys, or laminated films of these alloys. For example, Ni ₈₀ Fe ₂₀ , Ni ₅₀ Fe ₅₀ , FeSi, FeAlSi, FeTaC, CoNbZr, CoCrNb, CoTaZr, NiFeNb and the like can be used.

The soft magnetic shielding layer 51 has an easy magnetization axis in an in-plane direction. In particular, the magnetization axis direction is perpendicular to the track longitudinal direction, that is, perpendicular to the recording direction. It is possible to extremely suppress generation of magnetic walls serving as a noise source in the soft magnetic shielding layer 51. For example, when the vertical magnetic recording medium 50 is a magnetic disk, the easy magnetization axis is set in the radial direction, and in the case of the lateral magnetic tape, the easy magnetization axis is set in the width direction of the magnetic tape.

The soft magnetic shielding layer 51 is preferably a soft magnetic material having a magnetic permeability in the range of 20 to 2000. The followability to the high frequency recording magnetic field is improved.

In addition, the soft magnetic shielding layer 51 preferably has a saturation magnetization in the range of 0.1T to 2.4T. When it exceeds 2.4T, the selection range of the magnetic pole material of the recording head is limited.

In the soft magnetic shielding layer 51, when the saturation magnetic flux density of the magnetic material of the main magnetic pole of the recording head is Bs _H and the thickness of the main magnetic pole tip is t _H , the saturation magnetic flux density Bs of the soft magnetic shielding layer 51 is obtained. _S ) and the film thickness t _S are preferably set to Bs _S x t _S &_lt; Bs _H x t _H. The soft magnetic shielding layer 51 can be surely saturated by the magnetic field from the main magnetic pole.

In the vertical magnetic recording medium 50 of this embodiment, since the soft magnetic shielding layer 51 is provided on the recording layer 16, when the magnitude of the recording magnetic field is smaller than a predetermined amount, the recording magnetic field is the soft magnetic shielding layer ( Absorbed by 51) and cannot reach the recording layer. By making the recording magnetic field larger than or equal to the magnetic field for magnetically saturating the soft magnetic shielding layer 51, the recording magnetic field can pass through the soft magnetic shielding layer 51 to magnetize the recording layer.

10 is a diagram showing the shape of recording on the vertical magnetic recording medium according to the present embodiment. 10-12, illustration of the protective film 18 and the lubrication layer 19 is abbreviate | omitted.

Referring to FIG. 10, in recording, a recording magnetic field Hw is applied to the vertical magnetic recording medium 50 from the tip of the main magnetic pole 55 of the recording head opposite to the vertical magnetic recording medium 50 of the magnetic storage device. . When the recording magnetic field is applied, the magnetic flux from the recording head is absorbed by the soft magnetic shielding layer 51 and reaches the recording layer 16 when the recording magnetic field is less than or equal to the magnetic field that magnetically saturates the soft magnetic shielding layer 51. There is no. In addition, when the recording magnetic field increases, the region 51a of the soft magnetic shielding layer 51 facing the substantially center portion of the main magnetic pole front end portion is magnetically saturated. When magnetic saturation occurs, the recording magnetic field penetrates the soft magnetic shielding layer 51 to reach the recording layer 16 and further reaches the soft magnetic backing layer 12. In this way, a recording magnetic field is applied to the recording layer 16a to generate magnetization Ma. Here, the magnetic field Hwb leaking from the periphery of the main magnetic pole 55 tip is weak compared with the center portion, and this magnetic field Hwb is absorbed by the soft magnetic shielding layer 51. Since the magnetic field Hwa leaked from the center portion self-saturates the soft magnetic shielding layer 51, the size of the in-plane direction of the region 16a where the soft magnetic shielding layer 51 is saturated is larger than the size of the main magnetic pole tip portion 55. It can be made small.

FIG. 11 is a plan view of FIG. 10. Referring to FIG. 11, a region where the soft magnetic shielding layer 51 saturates is formed just below the front end of the main magnetic pole 55. A bit surrounded by the magnetization transition region 16a according to the recording signal is formed in accordance with the direction in which the vertical magnetic recording medium 50 moves (direction indicated by the arrow Mv). On the other hand, in the track width direction, a track Tkn having a width substantially equal to the width of the region where the soft magnetic shielding layer 51 is saturated can be formed. That is, the problem of eliminating magnetization of the adjacent tracks Tkn-1 and Tkn + 1, that is, side track erasure, can be solved by controlling the width of the saturation region 51a to the same extent as the track Tkn width. For example, the width of the saturation region 51a can be controlled by the recording current value, the magnetic permeability of the soft magnetic shielding layer 51, the film thickness, or the like.

12 is a diagram showing the reproduction of the vertical magnetic recording medium according to the present embodiment. Referring to Fig. 12, the reproducing head 56 uses an MR element formed by shielding the MR element along the moving direction of the vertical magnetic recording medium 50. As shown in Figs. When the reproduction head 56 is close to the perpendicular magnetic recording medium 50, the shield 58a-soft magnetic shield layer 51-is affected by the influence of the sense current flowing through the MR element and the magnetization of the soft magnetic shield layer 51. A magnetic field is generated in the shield 58b, and the soft magnetic shielding layer 51 facing the shields 58a and 58b and the region 51c therebetween can be self-saturated. In the soft magnetic shielding layer 51, the axis of easy magnetization is in the in-plane direction, and the direction of the magnetic field is in the in-plane direction in the soft magnetic shielding layer 51, so that the magnetic field can be magnetically saturated at a weak magnetic field. For example, in the soft magnetic material of Ni ₅₀ Fe ₅₀ , it can be magnetically saturated in a magnetic field of about 240 A / m. As a result, the magnetic field leaking out from the magnetization Ma of the lower recording layer 16 through the saturation region 51c of the soft magnetic shielding layer 51 reaches the MR element 59 of the reproduction head 56. . Therefore, the magnetization state of the recording layer 16 can be reproduced.

FIG. 13 is a plan view of FIG. 12. Referring to FIG. 13, the saturation region 51c of the soft magnetic shielding layer 51 becomes the soft magnetic shielding layer 51 facing the shields 58a and 58b and an area therebetween, and the MR element 59 The magnetic field leaking from the magnetization surrounded by the magnetization transition region 16a of the recording layer 16 can be reproduced. By making the width of the saturation region 51c the same as the track width, crosstalk from adjacent tracks Tkn-1 and Tkn + 1 can be reduced. In addition, the width of the MR element 59 may be made smaller than the width of the saturation region 51c.

Hereinafter, the manufacturing method of the vertical magnetic recording medium 50 according to the present embodiment will be described. The perpendicular magnetic recording medium 50 is formed from the soft magnetic support layer 12 to the recording layer 16 in the same manner as the method described in the first or second embodiment from the substrate 11 side shown in FIG. do.

The soft magnetic shielding layer 51 is implemented using a sputtering method, for example, a DC magnetron device. As the method of orienting the axis of easy magnetization in the vertical direction with respect to the movement direction at the time of recording the vertical magnetic recording medium 50, the following two methods can be used.

It is a figure which shows typically the film-forming apparatus which orients an easy magnetization axis by applying a magnetic field. Referring to FIG. 14, a magnetic pole 60N is disposed at the center of the vertical magnetic recording medium 50 and a magnetic pole 60S is disposed at the outer circumference to apply a direct current magnetic field Hap in the radial direction, and the vertical magnetic recording medium 50 is, for example, the Rt direction. The sputtering particles IB of the soft magnetic shielding layer 51 are made to enter while rotating. Here, the DC magnetic field is set at about 80 kA / m. In addition, although the DC magnetic field is shown to be applied to a part of the perpendicular magnetic recording medium 50 in the figure, the magnetic pole 60S of the outer periphery may be arrange | positioned to the whole outer periphery, and may be applied to the whole vertical magnetic recording medium 50. FIG.

It is a figure which shows typically the film-forming apparatus which orients an easy axis of magnetization by inclining sputtering particle and making it incident. Referring to Fig. 15, sputtering particles IB of the soft magnetic shielding layer 51 are incident while rotating the vertical magnetic recording medium 50, for example, in the Rt direction. Periphery of the perpendicular magnetic recording medium 50 with only the incident angle θin with respect to the surface where the incidence direction is formed by the main direction θr and the direction (Z direction) perpendicular to the perpendicular magnetic recording medium 50 plane Tilt in the direction. It is preferable to set the incident angle θin to be larger than 0 degrees and 60 degrees or less. Next, the protective film 18 and the lubrication layer 19 are formed similarly to 1st Embodiment.

As described above, the magnetic recording medium 50 can be formed in which the easy magnetization axis of the soft magnetic shielding layer 51 is oriented in a direction perpendicular to the moving direction at the time of recording.

According to this embodiment, a portion of the soft magnetic shielding layer 51 provided on the recording layer 16 forms a saturation region by the recording magnetic field and passes the recording magnetic field so that only the recording layer 16 under the saturation region becomes magnetic. can do. Therefore, expansion of the magnetic flux from the recording head can be suppressed, and adjacent track erasure can be prevented. In addition, since the magnetic flux from the recording head is concentrated, the recording magnetic field can be increased, and the writing performance of the recording layer can be improved.

16 is a schematic sectional view of a vertical magnetic recording medium according to a modification of the present embodiment. In the drawings, parts corresponding to the parts described above are denoted by the same reference numerals and description thereof will be omitted.

Referring to FIG. 16, the vertical magnetic recording medium 55 includes a substrate 11, a soft magnetic support layer 12, a seed layer 13, an underlayer 31, and a nonmagnetic intermediate layer 15 on the substrate 11. ), The recording layer 16, the nonmagnetic layer 52, the soft magnetic shielding layer 51, the protective film 18, and the lubrication layer 19 are sequentially stacked, and the recording layer 16 and the It is similar to the vertical magnetic recording medium of the third embodiment except that the nonmagnetic layer 52 is provided between the magnetic shielding layers 51.

The nonmagnetic layer 52 is formed by a sputtering method or the like, and has a thickness set in a range of 0.5 nm to 20 nm, and is made of a nonmagnetic material. The nonmagnetic material is not particularly limited, but for example, SiO ₂ , Al ₂ O ₃ , TiO ₂ , TiC, C, hydrogenated carbon, or the like can be used.

According to this embodiment, by providing a nonmagnetic layer between the recording layer 16 and the soft magnetic shielding layer 51, the magnetic coupling between the recording layer 16 and the soft magnetic shielding layer 51 can be prevented.

Hereinafter, the Example of this embodiment is shown.

Example 6

The perpendicular magnetic recording medium according to the present embodiment was configured as shown below. From the substrate side, the glass substrate / soft magnetic support layer: CoNbZr film (200 nm) / seed layer: Ta film (5 nm) / base layer: NiFe film (5 nm) / nonmagnetic intermediate layer: Ru film (20 nm) / recording layer: ( Co ₈₆ Cr ₈ Pt ₆ ) 90vol%-(SiO ₂ ) 10vol% film (10nm) / nonmagnetic layer: Ta film (4nm) / soft magnetic shielding layer: Ni ₈₀ Fe ₂₀ film (Xnm, saturated magnetic flux density 1.1T) / Protective film: Carbon film (10-Xnm) / Lubrication layer: AM 3001 (1.5 nm). Samples were prepared in which the film thickness (X) of the NiFe film of the soft magnetic shielding layer was varied from 0 to 10 nm. In addition, in order to make the distance from the recording head to the surface of the recording layer constant, the film thickness of the protective film was 10-Xnm with respect to the film thickness Xnm of the NiFe film. In addition, the CoNbZr film, the Ta film of the nonmagnetic layer, the NiFe film of the soft magnetic shielding layer, and the carbon film were formed using a DC magnetron sputtering device to form an Ar atmosphere gas and a pressure of 0.5 by using a sputtering apparatus in an Ar gas atmosphere. It set to Pa and formed into a film. In addition, the Ta film of the seed layer, the NiFe film of the underlying layer, and the Ru film had an Ar atmosphere gas and a gas pressure of 4.0 Pa using a DC magnetron sputtering apparatus. The recording layer used the RF magnetron sputtering apparatus, and made Ar atmosphere gas and gas pressure into 4.0 Pa. The substrate temperature at the time of film formation was room temperature. The lubricating layer was applied by the dipping method. In addition, the numerical value in the said parenthesis shows a film thickness.

FIG. 17 is a diagram showing a relationship between S / Nm and a soft magnetic shielding layer film thickness of Example 6. FIG. 17, it turns out that S / Nm becomes higher when it installs than when it does not provide a soft magnetic shielding layer (film thickness = 0). Further, by thickening the soft magnetic shielding layer film thickness, S / Nm increases, and the film thickness becomes maximum at 8 nm. As the film thickness increases, the amount of magnetic flux absorbing the magnetic flux from the recording head increases, so that the amount of magnetic flux leaks into the recording layer decreases, the area of the saturation region decreases, and the magnetic flux narrowed only in the narrowed saturation region is increased. As a result, the recording layer becomes magnetic, and as a result, it is assumed that the recording layer of a narrow range of the same size as the main magnetic pole is magnetized by the high recording magnetic field.

In addition, S / Nm is a composite magnetic head with a floating amount of 8 nm (write head: terminal pole head, light core width 0.2 μm, saturated magnetic flux density x light core thickness 0.4 μTm, recording current 5 mA, regeneration head (GMR element): lead The core density was measured using 0.12 µm), and the recording density was 500 kFCI. Moreover, the measurement conditions of FIG. 19, FIG. 20 mentioned later are also the same.

Fig. 18 is a diagram showing the relationship between the regeneration output reduction rate and the soft magnetic shielding layer film thickness of Example 6 in the adjacent track erase test. Referring to Fig. 18, it is known that the reduction rate of the reproduction output of the adjacent tracks is smaller than that in the case where no soft magnetic shielding layer is provided (film thickness = 0). It is also found that as the film thickness of the soft magnetic shielding layer increases, the rate of decrease of the regenerative output of adjacent tracks decreases monotonously. By doing so, it is known that the soft magnetic shielding layer suppresses magnetic flux leaking in the track width direction.

In addition, the adjacent track erase test records the measurement output at a recording density of 100 kFCI and measures the initial reproduction output (V ₀ ), and then repeats the DC erase operation 100 times by tracking the recording head 0.25 μm off, followed by the measurement track. The tracks were turned on and the playback output (V ₁ ) of the measurement track was measured, and the playback output reduction rate (%) = (V ₁ -V ₀ ) / V ₀ × 100%.

19 is a diagram showing a relationship between S / Nm and writing current in Example 6. FIG. In addition, in FIG. 17, the sample whose S / Nm shows the maximum value and the soft magnetic shielding layer film thickness is 8 nm was used.

Referring to Fig. 19, it is understood that S / Nm represents the maximum value with respect to the write current. From this, when the saturation region of the appropriate size is formed in the soft magnetic shielding layer, it is known that the magnetic flux from the recording head is concentrated and sufficient writing is performed.

Example 7

The perpendicular magnetic recording medium according to the present embodiment was configured as shown below. From the substrate side, the glass substrate / soft magnetic support layer: CoTaZr film (200 nm) / nonmagnetic intermediate layer: Ru film (20 nm) / recording layer: (Co ₇₉ Cr ₈ Pt ₁₃ ) 90 vol%-(SiO ₂ ) 10 vol% film ( 10 nm) / nonmagnetic layer: Ta film (Xnm) / soft magnetic shielding layer: Ni ₅₀ Fe ₅₀ film (20 nm, saturated magnetic flux density 1.3T) / protective film: carbon film (4 nm) / lubrication layer: AM3001 (1.5 nm) . A sample was prepared in which the film thickness (X) of the Ta film of the nonmagnetic layer was varied from 2 to 10 nm. In addition, film-forming conditions were carried out similarly to Example 6.

20 is a diagram showing a relationship between S / Nm and the nonmagnetic layer film thickness of Example 7. FIG. Referring to FIG. 20, S / Nm is the highest when the nonmagnetic layer film thickness is 2 nm (9.6 dB). We know that it is 1.4 dB higher than the case where no nonmagnetic layer is provided (film thickness = 0). In addition, S / Nm monotonously decreases as the thickness of the nonmagnetic layer increases. By providing a nonmagnetic layer from this, S / Nm can be improved by preventing magnetic coupling between the recording layer and the soft magnetic shielding layer.

(4th embodiment)

A vertical magnetic recording medium according to a fourth embodiment of the present invention in which ferrimagnetic or soft magnetic magnetic particles are arranged on a recording layer and the magnetic flux slit layer is described.

21 is a schematic cross-sectional view of a vertical magnetic recording medium according to the fourth embodiment of the present invention. In the drawings, parts corresponding to the parts described above are denoted by the same reference numerals and description thereof will be omitted.

Referring to FIG. 21, the vertical magnetic recording medium 50 includes a substrate 11, a soft magnetic support layer 12, a seed layer 13, an underlayer 31, and a nonmagnetic intermediate layer 15 on the substrate 11. The recording layer 16, the magnetic flux slit layer 71, the protective film 18, and the lubrication layer 19 are sequentially stacked.

The magnetic flux slit layer 71 is formed on the recording layer 16 described in the first or second embodiment, has a thickness of 2 nm to 20 nm, and has a nonmagnetic matrix in which ferrimagnetic or soft magnetic particles are made of a nonmagnetic material. Or it is formed surrounded by a nonmagnetic grain boundary, and is formed so that it may have an easy magnetization axis | shaft in a film thickness direction. Since the magnetic fine particles are separated by a nonmagnetic matrix or nonmagnetic particles in the in-plane direction, they are magnetically isolated and have an easy axis of magnetization in the film thickness direction. It is absorbed by ferri magnetic or soft magnetic magnetic particles having a higher magnetic permeability than the portion, and in particular by magnetic particles at the closest distance from the recording head. The absorbed magnetic flux passes through the recording layer 16 connected to the magnetic flux slit layer 71 and reaches the soft magnetic support layer 12. Therefore, the recording head substantially has the effect of connecting to the recording layer 16, and has the effect of increasing the recording magnetic field and inclining the spatial distribution of the recording magnetic field.

Specifically, the magnetic flux slit layer 71 is composed of a ferrimagnetic ferrite film, a ferrimagnetic ferrite particle or a granular film containing soft magnetic fine particles, or a soft magnetic nanocrystal film.

The ferrite magnetic ferrite film is preferably γ iron oxide (γ-Fe ₂ O ₃ ), magnetite (Fe ₃ O ₄ ), hexagonal flat barium ferrite (BaFe ₁₂ O ₁₉ ), and the like having a needle-like structure. These materials are used for a sputtering target, the substrate is heated and formed by the sputtering method, and after formation, magnetic anisotropy is imparted in the film thickness direction by heat treatment in a magnetic field.

In addition, as the granular film containing ferrimagnetic ferrite particles or soft magnetic particles, the ferrimagnetic ferrite particles may use the above-described particles such as γ-Fe ₂ O ₃ , Fe ₃ O ₄ , BaFe ₁₂ O ₁₉ , As the soft magnetic particles, a material containing at least one element selected from Co, Fe, and Ni may be used. The nonmagnetic mother phase is composed of at least one material selected from SiO ₂ , Al ₂ O ₃ , C, Fe ₃ O ₄ . For example, γ-Fe ₂ O ₃ particles and Fe ₃ O ₄ particles have a needle-like particle size, a length of about 10 nm in the longitudinal direction, and a coercive force in the longitudinal direction of 15.8 kA / m (2000e) to 35.6 kA / m (4500e), the saturation magnetization is 70 emu / g to 80 emu / g. BaFe ₁₂ O ₁₉ particles are hexagonal, about + nm in size, about 10 nm in thickness, coercive force in the thickness direction of 15.8 kA / m (2000e) to 47.4 kA / m (6000e), and saturation magnetization of 50 emu. / g to 58emu / g.

The soft magnetic nanocrystal film is formed of, for example, a FeMB (M = Zr, Hf, Nb) film, a FeMO (M = Zr, Hf, Nb, Y, Ce) film, or the like, and contains a large amount of α-Fe. And a nonmagnetic and amorphous grain boundary containing a large amount of M, B or O. The magnetic particles have a particle diameter in the in-plane direction of about 10 nm to 100 nm, and the grain boundary physically separates the magnetic particles from neighboring magnetic particles. See for example J.Appl.Phys. vol.81 (1997), as described in p2736, FeMB the Cu addition of 1 at% to (e. g., Fe ₈₄ Nb _{3 .5 .5} Zr ₃ B ₈ Cu ₁₎ and the optimization of the chemical synthesis This can improve the permeability and is effective for the refinement of crystals.

In the soft magnetic nanocrystal film, a FeZrB film having a thickness of 8 nm is formed on the recording layer 16 by, for example, sputtering. By heat-processing at low temperature before a crystallization process, the size of a crystal grain is provided and permeability can be improved.

According to this embodiment, since the magnetic flux slit layer 71 in which the magnetic particles surrounded by the nonmagnetic mother phase or the nonmagnetic grain boundary are arranged is provided on the recording layer 16, the magnetic flux slit layer 71 and the recording head from the recording head. The magnetic flux circulating through the recording layer 16 to the soft magnetic support layer 12 is constricted so as to pass the magnetic particles in the magnetic flux slit layer 71 to suppress the expansion of the magnetic flux from the recording head to the recording layer 16. To concentrate the magnetic flux. Therefore, erasure of adjacent tracks due to expansion of magnetic flux can be prevented, and track density can be improved. Also, the width of the magnetization transition region can be narrowed in the length direction of the track, and the recording density can be improved. As a result, a vertical magnetic recording medium of high recording density can be realized.

(5th embodiment)

A vertical magnetic recording medium according to a fifth embodiment of the present invention in which a magnetic flux slit layer in which nonmagnetic particles are arranged in a ferromagnetic mother phase is described.

22 is a schematic cross-sectional view of a vertical magnetic recording medium according to the fifth embodiment of the present invention. In the drawings, parts corresponding to the parts described above are denoted by the same reference numerals and description thereof will be omitted.

Referring to FIG. 22, the vertical magnetic recording medium 75 includes a substrate 11, a soft magnetic support layer 12, a seed layer 13, an underlayer 31, and a nonmagnetic intermediate layer 15 on the substrate 11. ), The recording layer 16, the magnetic flux slit layer 76, the protective film 18, and the lubrication layer 19 are sequentially stacked.

The magnetic flux slit layer 76 is 2 nm-10 nm in thickness, and is comprised by arrange | positioning the nonmagnetic fine particle 76b in the ferromagnetic mother phase 76a which consists of an alloy of a rare earth metal and a transition metal. The rare earth metal of the ferromagnetic mother phase 76a is selected from Tb, Gd, and Dy, and may contain one or two or more kinds. In addition, the transition metal may be selected from Fe and Co and may include one or two kinds. Examples of the ferromagnetic mother phase 76a include TbFeCo, GdFeCo, and DyFeCo. In the case of an alloy of rare earth and FeCo, (Tb, Gd, Dy, or these alloys) x (Fe100-yCoy) 100-x When shown, it is preferable to set x = 10 atomic%-30 atomic% and y = 40 atomic% or less. In such a range, the easy axis of magnetization of the ferromagnetic mother phase becomes the film thickness direction, so that the magnetic flux can pass in response to the increase and decrease of the magnetic flux from the recording head. As a result, magnetic saturation of the ferromagnetic mother phase can be avoided and the magnetic flux can be confined.

The nonmagnetic fine particles 76b are formed from a compound of any one element of the group consisting of Si, Al, Ta, Zr, Y, and Mg, and at least one element of the group consisting of O, C, and N. Is selected. Specifically, it selects from the material substantially the same as the 2nd non-employment phase 42b of 2nd Embodiment. Since these oxides, nitrides, carbides, and the like form a covalent compound, they are easily separated into the rare earth metal-transition metal alloy material constituting the ferromagnetic mother phase 76a, and are precipitated into fine particles in the ferromagnetic mother phase 76a. That is, the nonmagnetic fine particles 76b are self-forming in the ferromagnetic mother phase 76a.

The nonmagnetic fine particles 76b preferably contain Y (Yttrium). When the nonmagnetic fine particles 76b contain oxygen, it inhibits the formation of a selective bond of the rare earth metal and oxygen (for example, Tb-O) in the ferromagnetic mother phase 76a, and the saturated magnetic flux of the ferromagnetic mother phase 76a. The fall of density can be prevented.

It is preferable that the average particle diameter of the nonmagnetic fine particles 76b is set within the range of 3 nm to 10 nm, and the average interval between the nonmagnetic fine particles and the adjacent nonmagnetic fine particles is set within the range of 0.5 nm to 10 nm. By setting in such a range, it is possible to narrow the magnetic flux sufficiently with respect to the size of the bit to be recorded.

The magnetic flux slit layer 76 is formed by a vacuum deposition method, a sputtering method, or the like, and is formed by, for example, sputtering using a sputtering target of TbFeCo and a YSi ₅ O ₂ sputtering target at the same time. As an example of this embodiment, using an RF magnetron sputtering apparatus, TbFeCo (20 atomic% Tb-72 atomic% Fe-8 atomic% Co) and YSiO₂ sputtering target are simultaneously sputtered on the recording layer, and the magnetic flux slit layer ( Based on the volume of 76), the magnetic flux slit layer 76 having 70 vol% of YSiO2 and a thickness of 10 nm was formed. As the sputtering target, a composite sputtering target obtained by mixing TbFeCo and YSiO 2 may be used in addition to the two sputtering targets.

According to this embodiment, since the magnetic flux slit layer 76 in which the nonmagnetic fine particles 76b are disposed in the ferromagnetic mother phase 76a is provided on the recording layer 16, the magnetic flux slit layer 76 and The magnetic flux circulating through the recording layer 16 to the soft magnetic support layer 12 is constricted so as to pass through the ferromagnetic matrix 76a between the magnetic flux slit layer 76 and the nonmagnetic particles 76b, and from the recording head to the recording layer. We suppress expansion of magnetic flux over (16) and can concentrate magnetic flux. Therefore, erasure of adjacent tracks due to expansion of magnetic flux can be prevented, and track density can be improved. Also, the width of the magnetization transition region can be narrowed in the length direction of the track, and the recording density can be improved. As a result, a vertical magnetic recording medium of high recording density can be realized.

23 is a schematic sectional view of a vertical magnetic recording medium according to a modification of the fifth embodiment.

The vertical magnetic recording medium 80 according to the present modification includes a substrate 11 and a soft magnetic support layer 12, a seed layer 13, an underlayer 31, and a nonmagnetic intermediate layer 15 on the substrate 11. The recording layer 16, the magnetic flux slit layer 81, the protective film 18, and the lubrication layer 19 are sequentially stacked. Instead of the magnetic flux slit layer 76 shown in FIG. A magnetic flux slit layer composed of a crystal growth nucleus 81b made of a nonmagnetic material formed on the surface of the surface 16 and a soft magnetic base layer 81a of a soft magnetic material filled in a gap between adjacent crystal growth nuclei 81b ( The same as the vertical magnetic recording medium according to the fifth embodiment except that 81 is provided.

The crystal growth nuclei 81b of the magnetic flux slit layer 81 are made of Al, Ta, Ti, Ag, Cu, Pb, Si, B, Zr on the surface of the recording layer 16 by sputtering, vacuum deposition, CVD, or the like. And nonmagnetic materials selected from Cr, Ru, Re and alloys thereof. The crystal growth nucleus 81b is a crystal growth nucleus formed at the beginning of the film formation process, and the size of the crystal growth nucleus 81b or the distance between the crystal growth nuclei 81b and the adjacent crystal growth nucleus 81b is determined by substrate temperature, deposition amount, and deposition. The speed can be controlled.

The soft magnetic matrix layer 81a is filled with a soft magnetic material of high saturation magnetic flux density, for example, substantially the same as the soft magnetic support layer 12. In addition, the thickness of the soft magnetic matrix layer 81a is preferably thinner than the thickness of the crystal growth nuclei 81b. The expansion of the magnetic flux can be prevented and can be narrowed effectively.

According to this modification, since the crystal growth nuclei 81b made of a nonmagnetic material is arranged in isolation from the soft magnetic matrix layer 81a between the recording layer 16 and the protective film 18, at the time of recording, the recording head The magnetic flux from is confined to the soft magnetic material filled between the crystal growth nuclei 81b to suppress the expansion of the magnetic flux and to concentrate the magnetic flux on the recording layer 16. Further, a nonmagnetic layer having a thickness of 1.0 to 5.0 nm may be formed between the magnetic flux slit layers 76 and 81 and the recording layer 16. Magnetic interaction between the magnetic flux slit layers 76 and 81 and the recording layer 16 can be cut off.

(6th Embodiment)

A vertical magnetic recording medium according to a sixth embodiment of the present invention in which a tip-shaped magnetic material made of a soft magnetic material is disposed in an in-plane direction between a soft magnetic support layer and a recording layer.

24 is a schematic cross-sectional view of a vertical magnetic recording medium according to the sixth embodiment of the present invention. In the drawings, parts corresponding to the parts described above are denoted by the same reference numerals and description thereof will be omitted.

Referring to FIG. 24, the vertical magnetic recording medium 90 according to the present embodiment includes a substrate 11, a soft magnetic support layer 12, a nonmagnetic intermediate layer 15, and a tip-shaped magnetic body 91 on the substrate 11. ), The recording layer 16, the protective film 18, and the lubrication layer 19 are laminated in this order.

The tip-shaped magnetic body 91 is formed of a ferrimagnetic material or a soft magnetic material having a coercive force of 79 k5 A / m or less, for example, formed by the sputtering method, and has an easy magnetization axis in the film thickness direction. As a method of orienting an easy magnetization axis in a film thickness direction, the material which an easy magnetization axis orients in a film thickness direction, for example, 19 atomic%-28 atomic% Gd-Fe film, 20 atomic%-30 atomic% Nd-Fe film, 20 atomic%-30 atomic% Nd-Co film | membrane is mentioned. By forming using a sputtering method, for example, the DC magnetron sputtering method, the axis of easy magnetization can be oriented in the film thickness direction. The tip magnetic material 91 may be a CoCr film using a Ru film or a Pd film as the nonmagnetic intermediate layer 15.

The tip magnetic material 91 is, for example, 0.6 nm to 20 nm in size, 2 nm to 10 nm thick, and has a thickness of 0.6 nm to 20 nm between adjacent tip magnetic bodies 91. It is arranged almost uniformly on the surface of the intermediate layer 15. The tip-shaped magnetic body 91 is preferably set to a size and an interval at which at least two tip-shaped magnetic bodies 91 are arranged with respect to the size of the recording bit formed in the recording layer 16. Magnetic flux from the recording head can be concentrated in the recording layer 16.

25 is a plan view of a vertical magnetic recording medium 90 according to the sixth embodiment. Referring to FIG. 25, the pattern 18a of the tip-shaped magnetic body 91 appears on the upper surface of the protective film 18 of the perpendicular magnetic recording medium 90, and functions as a so-called texture. When the magnetic head (not shown) stops on the surface of the vertical magnetic recording medium 90, the magnetic head can be prevented from adsorbing.

Next, the method of forming the tip-shaped magnetic body 91 is shown below.

First, on the nonmagnetic intermediate layer 15, a soft magnetic layer serving as the tip magnetic material 91 is formed by sputtering, vapor deposition, or the like. Subsequently, the electron beam register film is applied using a spin coater, and after baking, the texture pattern drawn on the stencil mask having a reduced magnification of 4 times is transferred by an electron beam batch projection exposure method.

Next, a post-exposure bake treatment is performed and developed to form a resist pattern. Using the resist pattern as a mask, the soft magnetic layer is etched by ion milling until it reaches a nonmagnetic intermediate layer. The resist pattern is then removed.

By this process, since the address unit of the current mask data is patterned at 2.5 nm and reduced magnification 4 times, it is possible to form the tip-shaped magnetic body 91 up to a size of at least about 0.6 nm.

In addition, the tip-shaped magnetic body 91 may be the square pattern 18b shown in FIG. 26 instead of the circular pattern obtained by the planar view shown in FIG. The pattern 18b is formed so that the vicinity of the pattern 18b perpendicularly crosses the moving direction Mv of the vertical magnetic recording medium 90 indicated by the arrow. By controlling the shape and height of the tip-shaped magnetic body 91 with respect to the moving direction Mv, the possibility of the magnetic head connecting to the surface of the vertical magnetic recording medium 90 and colliding with each other can be reduced.

In addition, a nonmagnetic layer may be formed between the tip-shaped magnetic material 91 and the recording layer 16. The magnetic coupling between the tip-shaped magnetic body 91 and the recording layer 16 can be cut off. In addition, the tip-shaped magnetic body 91 may be covered with a nonmagnetic layer, and the tip-shaped magnetic body 91 may be reduced by an etching method or a chemical mechanical polishing method to adjust the unevenness formed by the tip-shaped magnetic body 91. The roughness of the surface of the perpendicular magnetic recording medium 90 can be reduced, and the texture effect can be controlled.

According to this embodiment, the tip-shaped magnetic body 91 is provided between the soft magnetic support layer 12 and the recording layer 16, and the tip-shaped magnetic body 91 has an easy magnetization axis in the film thickness direction, so that the recording head The magnetic flux from can be concentrated by the tip-shaped magnetic body 91, the magnetic flux can be concentrated in the recording layer 16, and the magnetic field inclination can be urgent. In addition, since the shape of the tip-shaped magnetic material 91 is transferred in the film thickness direction, an uneven texture pattern is formed on the surface of the vertical magnetic recording medium 90 to prevent the magnetic head from adsorbing on the surface, and also the head collision. The possibility of this occurring can be reduced.

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 (Ninth embodiment)

A ninth magnetic memory device of the present invention having a vertical magnetic recording medium according to the first to sixth embodiments will be described.

33 is a diagram showing the main parts of a magnetic memory device of the embodiment of the present invention. Referring to FIG. 33, the magnetic memory device 120 is almost housed. In the housing 121, a hub 122 driven by a spindle (not shown), a vertical magnetic recording medium 123 fixed and rotated to the hub 122, an actuator unit 124, and an actuator unit 124 are provided. An arm 125, a suspension 126, and a vertical magnetic recording head 128 supported by the suspension 126 are provided to be attached and moved in the radial direction of the vertical magnetic recording medium 123.

34 is a schematic sectional view of a vertical magnetic recording head and a vertical magnetic recording medium. Referring to FIG. 34, the vertical magnetic recording head 128 includes a recording head 130 composed of a main magnetic pole 135 and a return yoke 136 and a reproduction head 131 using a Giant Magneto Resistive (GMR) element 133. It consists of). The recording head 130 includes a main magnetic pole 135 made of a soft magnetic material for applying a recording magnetic field to the vertical magnetic recording medium 123, a return yoke 136 magnetically connected to the main magnetic pole 135, and a main magnetic pole. And a recording coil 138 for inducing a recording magnetic field in the magnetic pole 135 or the like. It is also composed of the GMR element 133 fitted to the lower shield and the upper shield 137 using the reproduction head 131 and the return yoke 136.

The recording head 130 applies a recording magnetic field in a vertical direction with respect to the vertical magnetic recording medium 123 from the tip portion 135-1 of the main magnetic pole, and forms a magnetization in the vertical direction in the recording layer (not shown). In addition, the magnetic flux from the tip 135-1 of the main magnetic pole also flows back to the return yoke 136 through a soft magnetic support layer (not shown). The soft magnetic material of the tip portion 135-1 of the main magnetic pole has a high saturation magnetic flux density, and is preferably made of 50at% Ni-50at% Fe, FeCoNi alloy, FeCoAlO, or the like. By preventing magnetic saturation, the magnetic flux of high magnetic flux density can be concentrated and applied to the recording layer 130.

The reproduction head 131 also detects a magnetic field leaked by the magnetization of the vertical magnetic recording medium 123, and obtains the information recorded in the recording layer by the change in the resistance value of the GMR element 133 corresponding to the direction. Can be. Instead of the GMR element 133, a ferromagnetic tunnel magneto resistive (TMR) element or a ballistic MR element may be used.

The magnetic memory device 120 of this embodiment is characterized by the vertical magnetic recording medium 123. For example, the vertical magnetic recording medium 123 is a vertical magnetic recording medium according to the first to sixth embodiments and modifications thereof.

The basic configuration of the magnetic memory device 120 is not limited to that shown in FIG. The vertical magnetic recording medium 123 used in the present invention is not limited to a magnetic disk but may be a magnetic tape.

According to the present embodiment, the magnetic memory device 120 narrows the tracks and lines by allowing the vertical magnetic recording medium 123 to further narrow the magnetic flux from the main magnetic pole 135 of the recording head 130 to the recording layer. The recording density can be improved, and high density recording is possible.

As mentioned above, although preferred embodiment of this invention was described above, this invention is not limited to this specific embodiment, A various deformation | transformation and a change are possible within the scope of this invention described in a claim.

For example, in the magnetic memory device according to the ninth embodiment, a magnetic disk is used as an example of a vertical magnetic recording medium. However, the vertical magnetic recording medium of the present invention is not limited to the magnetic disk. Using a film made of mid, a helical scanning or lateral traveling type magnetic tape may be used, or a card may be used.

According to the present invention, by providing a magnetic flux slit layer, a magnetic shielding layer, or a magnetic flux control layer between the soft magnetic support layer and the recording layer or on the recording layer, the expansion of the magnetic flux from the recording head is suppressed, and the recording magnetic field is increased while recording It is possible to realize a vertical magnetic recording medium capable of steeping the magnetic field and enabling high density recording.

In addition, by providing a nonmagnetic intermediate layer that controls the particle size and distribution of the magnetic particles of the recording layer between the soft magnetic support layer and the recording layer, it is possible to simultaneously promote the miniaturization and isolation of the crystal grains of the recording layer, thereby increasing the S / N. The vertical magnetic recording medium capable of high density recording can be realized.

Claims (56)

Soft magnetic backing layer, A vertical magnetic recording medium having a recording layer provided on the soft magnetic support layer, A magnetic flux slit layer between the soft magnetic support layer and the recording layer, The magnetic flux slit layer is a soft magnetic layer having a columnar structure magnetically isolated in an in-plane direction, And in-plane magnetic anisotropy of the magnetic flux slit layer is equal to or greater than in-plane magnetic anisotropy of the soft magnetic support layer. The method of claim 1, Further having a nonmagnetic intermediate layer between the flux slit layer and the recording layer, And the recording layer is formed by epitaxial growth on the nonmagnetic intermediate layer. The method of claim 2, The nonmagnetic intermediate layer has a hcp crystal structure, while the (001) plane is the crystal growth direction, And the magnetic flux slit layer has a hcp crystal structure or an fcc crystal structure. The method of claim 1, And said magnetic flux slit layer has in-plane magnetic anisotropy greater than vertical magnetic anisotropy. The method of claim 4, wherein And the anisotropic magnetic field of the in-plane magnetic anisotropy is greater than 711 kA / m. The method of claim 1, And the magnetic flux slit layer comprises crystal grains of the columnar structure and grain boundaries formed between the crystal grains. The method of claim 6, A vertical magnetic recording medium, wherein the main component forming the grains and the grain boundary are the same. The method of claim 7, wherein And the amount of the inert gas contained in the grain boundary is greater than the amount of the inert gas contained in the crystal grains. The method of claim 1, The magnetic flux slit layer has at least one of Co, Fe, Ni, Co-based alloys, Fe-based alloys, and Ni-based alloys as a main component. The method of claim 9, The magnetic flux slit layer further comprises any one of a group consisting of Al, Ta, Ag, Cu, Pb, Si, B, Zr, Cr, Ru, Re, Nb, and C. . The method of claim 1, And the magnetic flux slit layer is formed on and in contact with the soft magnetic support layer. delete The method of claim 1, The recording layer includes magnetic particles having a columnar structure and a non-magnetic non-solid phase surrounding the magnetic particles, And the non-employed phase is made of any one of an oxide, a nitride, and a carbide. Soft magnetic support layer, A method of manufacturing a vertical magnetic recording medium having a recording layer provided on the soft magnetic support layer, Forming a soft magnetic support layer; Forming a recording layer; Between the process of forming the soft magnetic support layer and the process of forming the recording layer, a magnetic flux slit layer made of a soft magnetic material in an atmosphere gas having a pressure equal to or higher than the pressure of the atmosphere gas used in the process of forming the recording layer. Further comprising a step of forming a, The in-plane magnetic anisotropy of the magnetic flux slit layer is equal to or greater than the in-plane magnetic anisotropy of the soft magnetic support layer. The method of claim 14, The atmospheric gas pressure is set in a range of 1 Pa to 8 Pa. The method of claim 14, And a substrate temperature is set to 150 [deg.] C. or less in the step of forming the magnetic flux slit layer. A magnetic memory device comprising the vertical magnetic recording medium according to claim 1 and recording and reproducing means. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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