JP2006216144A - Magnetic recording medium, initialization method thereof, and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic recording medium capable of enhancing the effect of reducing magnetic interference between tracks.
A magnetic recording layer is formed on a substrate made of a nonmagnetic material. In the magnetic recording layer, a plurality of track areas in which data is recorded and a guard band area arranged between adjacent track areas are defined. The magnetic recording layer in the track region exhibits magnetic anisotropy that is more easily magnetized in the vertical direction than in the in-plane direction, and the magnetic recording layer in the guard band region has a magnetic anisotropy that is more easily magnetized in the in-plane direction than in the vertical direction. Show direction.
[Selection] Figure 1

Description

  The present invention relates to a magnetic recording medium, an initialization method thereof, and a manufacturing method thereof, and in particular, a magnetic recording medium provided with a guard band for reducing magnetic interference between adjacent tracks, an initialization method thereof, and the same It relates to a manufacturing method.

  FIG. 8A shows a partially broken perspective view of the magnetic recording medium disclosed in Patent Document 1 below. A track region 101 and a guard band region 102 are defined on the surface of the glass substrate 100. The guard band region 102 is disposed between two track regions 101 adjacent to each other. The guard band region 102 is formed on the Cu or Cr thin film 103. In the track region 101, a perpendicular magnetic recording film 104 such as a CoCr alloy is formed on a glass substrate 100.

  In order to make it easier to write information in the track area 101, a high permeability thin film is formed under the track area 101. In addition, when the information stored in the track area 101 is read, the signal output due to the magnetic flux leaking from the guard band area 102 becomes sufficiently small, so that good off-track characteristics can be obtained.

  FIG. 8B shows a partially broken perspective view of the magnetic recording medium disclosed in Patent Document 2 below. A plurality of grooves 111 are formed on the surface of the substrate 110, and a convex portion between two adjacent grooves 111 becomes a track area 112 for recording data. The read head 113 reads the data recorded in the track area 112. Since the tracks are separated by the groove 111, the interference of the magnetic field between the tracks can be reduced. Also, a magnetic recording film is provided in the groove 111, and servo information is recorded on this magnetic recording film.

  FIG. 8C shows a cross-sectional view of the magnetic recording medium disclosed in Patent Document 3 below. A soft magnetic backing layer 121 is formed on the nonmagnetic substrate 120. A plurality of grooves 122 are formed on the surface of the soft magnetic backing layer 121. A nonmagnetic material 123 is filled in the groove 122. A perpendicular magnetic recording film 124 is formed on the soft magnetic underlayer 121 and the nonmagnetic material 123. A region between two adjacent grooves 122 becomes a data track 125. A nonmagnetic material 123 disposed between two data tracks 125 adjacent to each other magnetically separates the data tracks 125 adjacent to each other.

JP 61-237231 A JP-A-3-142707 JP 2003-16621 A

  If the surface is uneven as in the magnetic recording medium disclosed in Patent Document 2, the head flying becomes unstable due to the unevenness, which increases the risk of head crash. In the magnetic recording medium described in Patent Document 3, irregularities are not formed on the surface, so that the head flying is stable. However, since the area on the nonmagnetic material 123 is also the perpendicular magnetic recording film 124 and is made of the same material as the data track, information is recorded in an area wider than the track width. Further, since the area on the nonmagnetic material 123 and the data track are the same material, it is difficult to detect the position of the data track from the head when information is first recorded. For this reason, it becomes difficult to discriminate the track, and the position of the head becomes difficult.

Further, the magnetic recording medium disclosed in Patent Document 1 has an insufficient function to prevent magnetic interference between tracks when the track pitch is narrowed.
An object of the present invention is to provide a magnetic recording medium capable of enhancing the effect of reducing magnetic interference between tracks. Another object of the present invention is to provide an initialization method and a manufacturing method for the magnetic recording medium.

  According to one aspect of the present invention, a substrate made of a non-magnetic material, a magnetic recording layer formed on the substrate, and a plurality of track regions in which data is recorded, between adjacent track regions. The magnetic recording layer in the track region exhibits magnetic anisotropy that is easily magnetized in the direction perpendicular to the in-plane direction, and the magnetic recording in the guard band region A magnetic recording medium having a magnetic recording layer having magnetic anisotropy that is more easily magnetized in the in-plane direction than in the perpendicular direction is provided.

  According to another aspect of the present invention, a magnetic recording layer including a substrate made of a non-magnetic material and a magnetic material disposed on the substrate and having a hexagonal close-packed crystal structure, wherein data is recorded. Track regions and guard band regions disposed between adjacent track regions, in which the c-axis of the magnetic material in the magnetic recording layer is perpendicular to the substrate surface. And a magnetic recording layer having a c-axis preferentially oriented in a direction parallel to the substrate surface in the guard band region.

  According to still another aspect of the present invention, a plurality of track areas in which data is recorded and a guard band area disposed between adjacent track areas are defined, and magnetic recording in the track areas is defined. The layer exhibits magnetic anisotropy that is more easily magnetized in the perpendicular direction than in the in-plane direction, and the magnetic recording layer in the guard band region exhibits magnetic anisotropy that is more easily magnetized in the in-plane direction than in the perpendicular direction. A step of preparing a recording medium, and applying a magnetic field that is greater than the coercive force of the magnetic material forming the magnetic recording layer and that is perpendicular to the magnetic recording layer, to make the magnetic recording layer magnetically A method for initializing a magnetic recording medium.

  According to still another aspect of the present invention, (a) a surface of a substrate in which a plurality of track regions and a guard band region disposed between adjacent track regions are defined on the surface; A step of forming a base layer made of a non-magnetic material, and (b) filling the track region between the base layers with a soft magnetic material until the top surface is higher than the top surface of the base layer. Forming a member; (c) depositing a nonmagnetic material on the underlayer and the soft magnetic member to form an upper layer; and (d) exposing the soft magnetic member in the track region. A step of planarizing the surface so that the upper layer remains in the guard band region; and (e) a step of forming an upper alignment control layer made of a nonmagnetic material on the planarized surface; ) On the upper orientation control layer, magnetic Method of manufacturing a magnetic recording medium and a step of forming a magnetic recording layer containing the material is provided.

  According to still another aspect of the present invention, (p) a nonmagnetic material is formed on a substrate having a plurality of track regions and a guard band region disposed between adjacent track regions on a surface. Forming a guard band lower alignment control layer comprising: (q) forming a groove reaching at least a bottom surface of the guard band lower alignment control layer in the track region; and (r) the groove. And (s) a non-magnetic material on the lower alignment control layer for the guard band and the lower alignment control layer for the track. There is provided a method of manufacturing a magnetic recording medium, comprising: forming an upper alignment control layer, and (t) forming a magnetic recording layer containing a magnetic material on the upper alignment control layer.

  Since the magnetic recording layer in the guard band region is preferentially magnetized in the in-plane direction, the leakage magnetic flux from the guard band region hardly affects the signal read from the magnetic recording layer in the perpendicularly magnetized track region. For this reason, medium noise can be reduced. In addition, since the guard band region is disposed between the track region to be read and the track region adjacent thereto, the magnetic influence from the adjacent track region can be reduced. Thereby, excellent read / write characteristics (R / W characteristics) can be obtained.

  FIG. 1 shows a partially broken perspective view of a magnetic recording medium according to the first embodiment. The horizontal direction (X direction) in FIG. 1 corresponds to the radial direction (track width direction), the depth direction (Y direction) corresponds to the circumferential direction (track length direction), and the vertical direction (Z direction) corresponds to FIG. This corresponds to the thickness direction of the magnetic recording medium.

A concentric track region 11 is defined on the surface of the substrate 1 made of a nonmagnetic material such as glass. A guard band region 12 is formed between adjacent track regions 11.
A backing layer 2 made of a soft magnetic material is disposed on the substrate 1. The backing layer 2 is formed of an amorphous alloy such as CoNiFeB, and has a thickness of 100 nm, for example. On the backing layer 2, a lower orientation control layer 3, an upper orientation control layer 4, and a magnetic recording layer 5 are laminated in this order.

  The lower alignment control layer 3 has different stacked structures in the track region 11 and the guard band region 12. The lower orientation control layer 3 in the track region 11 is composed of a soft magnetic layer 9 made of a soft magnetic material whose lattice shape is a face-centered cubic lattice (fcc). The soft magnetic layer 9 is made of, for example, CoNiFeB and has a thickness of 150 nm. The lower orientation control layer 3 in the guard band region 12 has a layer structure in which a base layer 6, an intermediate layer 7, and an upper layer 8 are laminated in this order. The underlayer 6 is made of a nonmagnetic material such as polymethyl methacrylate (PMMA), and has a thickness of 100 nm, for example. The middle layer 7 is made of a nonmagnetic material whose lattice shape is a body-centered cubic lattice, for example, an AlCr alloy, and has a thickness of about 30 nm. The upper layer 8 is made of a nonmagnetic material whose lattice shape is a body-centered cubic lattice, such as Cr, and has a thickness of 3 to 10 nm.

  The upper orientation control layer 4 is formed of a nonmagnetic material whose crystal structure is a hexagonal close-packed structure (hcp), for example, ruthenium (Ru) or an alloy containing Ru, and has a thickness of 15 nm. In the track region 11 whose base surface is a soft magnetic material having a face-centered cubic lattice, the c-axis of the nonmagnetic material forming the upper orientation control layer 4 is preferentially oriented in the direction perpendicular to the substrate surface. In contrast, in the guard band region 12 whose base surface is a non-magnetic material having a body-centered cubic lattice, the c-axis is preferentially oriented in a direction parallel to the substrate surface.

  This orientation can be confirmed by analysis using X-ray diffraction. For example, a sharp peak corresponding to the (002) plane of Ru appears in the X-ray diffraction pattern of the Ru layer formed on the CoNiFeB amorphous alloy layer. On the other hand, a clear peak corresponding to the (002) plane of Ru does not appear in the X-ray diffraction pattern of the Ru layer formed on the PMMA layer, the AlCr alloy layer, and the Cr layer.

  The magnetic recording layer 5 is a perpendicular magnetization film having a granular structure in which a large number of magnetic metal grains are dispersed in a nonmagnetic material. The nonmagnetic material serving as the base is, for example, silicon oxide, and the magnetic metal grains are formed of a magnetic metal having a hexagonal close-packed crystal structure, such as a CoCrPt alloy. The thickness of the magnetic recording layer 5 is, for example, 15 nm.

  The magnetic metal grains in the magnetic recording layer 5 take over the crystal orientation of the underlying surface and grow epitaxially. For this reason, the c-axis of the crystal forming the magnetic metal grains in the track region 11 is preferentially oriented in a direction perpendicular to the substrate surface. The c-axis of the crystal forming the magnetic metal grains in the guard band region 12 is preferentially oriented in a direction parallel to the substrate surface.

  The magnetic recording layer 5 in the track region 11 exhibits magnetic anisotropy that is more easily magnetized in the perpendicular direction than in the in-plane direction. On the other hand, the magnetic recording layer 5 in the guard band region 12 exhibits magnetic anisotropy that is more easily magnetized in the in-plane direction than in the perpendicular direction. Here, “shows magnetic anisotropy that is more easily magnetized in the vertical direction than in the in-plane direction” means that the residual magnetic flux density when a vertical magnetic field is applied is the residual magnetic flux density when an in-plane magnetic field is applied. It means that it is larger than the magnetic flux density.

Next, a method for manufacturing a magnetic recording medium according to the first embodiment will be described with reference to FIGS.
As shown in FIG. 2A, a CoNiFeB backing layer 2 is formed on the surface of the substrate 1 by sputtering using a CoNiFeB target. A PMMA film is formed on the backing layer 2, and this PMMA film is patterned by electron beam drawing or imprinting. As a result, the base layer 6 made of PMMA is formed in the guard band region 12. The surface of the backing layer 2 is exposed in the track region 11.

  As shown in FIG. 2B, a soft magnetic layer 9 is formed on the track region 11 of the backing layer 2 by plating. The soft magnetic layer 9 has a thickness such that its upper surface is higher than the upper surface of the underlayer 6. The difference in height between the upper surface of the soft magnetic layer 9 and the upper surface of the underlayer 6 is larger than the total thickness of the middle layer 7 and the upper layer 8 shown in FIG. The soft magnetic layer 9 is not formed on the upper surface of the underlayer 6.

  On the soft magnetic layer 9 and the underlayer 6, an intermediate layer 7 made of AlCr alloy having a thickness of about 30 nm and an upper layer 8 made of Cr having a thickness of 3 to 10 nm are formed by sputtering. It is preferable to promote crystallization of AlCr and Cr by heating the substrate to about 150 ° C. to 200 ° C. during film formation.

  As shown in FIG. 2C, the surface is flattened so that the soft magnetic layer 9 is exposed in the track region 11 and a part of the upper layer 8 remains in the guard band region 12. This planarization process can be performed by, for example, chemical mechanical polishing (CMP) or ion etching. In the case of performing ion etching, planarization can be performed by a technique called etch back. For example, a material (resist, etc.) having an etching rate different from that of the material to be etched (upper layer 8, middle layer 7) is formed, etched by ion etching (ion beam etching, etc.), and planarized using the difference in etching rate can do. As a result, the lower orientation control layer 3 having a single layer structure composed of the soft magnetic layer 9 in the track region 11 and a three-layer structure of the base layer 6, the middle layer 7, and the upper layer 8 in the guard band region 12. It is formed.

  As shown in FIG. 2D, an upper orientation control layer 4 made of Ru or a Ru alloy is formed on the lower orientation control layer 3 by sputtering. The substrate temperature is room temperature. A magnetic recording layer 5 having a granular structure is formed on the upper orientation control layer 4 by sputtering. The magnetic recording layer 5 is formed under the condition that the magnetic metal grains in the granular structure grow while taking over the crystal orientation of the underlying surface.

Next, the effects of the magnetic recording medium according to the first embodiment will be described with reference to FIGS. 3 (A) and 3 (B).
FIG. 3A is a schematic diagram of the magnetic recording layer 5 and the read head 20 having a structure in which the tracks are in contact with each other without providing the guard band region. Another track 11B is adjacent to both sides of the track 11A to be read. Magnetic recording in the vertical direction is performed on both the read target track 11A and the adjacent track 11B. For this reason, the leakage magnetic flux from the adjacent track 11B becomes a medium noise source.

  FIG. 3B is a schematic diagram of the magnetic recording layer 5 and the read head 20 of the magnetic recording medium according to the first embodiment. A guard band region 12 is arranged between the read target track 11A and the adjacent track 11B. The magnetic recording layer 5 in the guard band region 12 is preferentially magnetized in the in-plane direction. For this reason, the leakage magnetic flux from the guard band region 12 hardly affects the read signal. Thereby, it becomes possible to reduce the medium noise.

Next, with reference to FIGS. 4A to 4C, the initialization method and the track identification method of the magnetic recording medium according to the first embodiment will be described.
4A shows an example of the magnetization state of the track region 11 of the magnetic recording film 5 and the relationship between the read signal waveform, and FIG. 4B shows the magnetization state of the guard band region 12 of the magnetic recording layer 5. And a readout signal waveform caused by a leakage magnetic field from the guard band region 12 is shown. The horizontal axis in FIGS. 4A to 4C corresponds to the track length direction (Y direction).

  In the perpendicularly magnetized track region 11, the magnetization intensity is directly reflected in the magnitude of the read signal. When the magnetic flux for perpendicular magnetization leaks to the guard band region 12, the guard band region 12 is preferentially magnetized in the in-plane direction due to the change of the magnetic flux. In the guard band region 12 magnetized in the in-plane direction, a change in magnetic flux when the magnetization direction is reversed is detected as a read signal.

  Consider a case where the magnetic recording medium according to the first embodiment is initialized (AC erasure) with an alternating magnetic field. In the track region 11, as shown in FIG. 4A, the upward and downward magnetization areas appear alternately. When reading is performed with a GMR head or the like, the read signal has a sinusoidal envelope. In the guard band region 12, the magnetization direction in the in-plane direction changes according to the alternating magnetic field. As shown in FIG. 4B, the read signal has a waveform having a peak when the direction of the magnetic field is reversed. The signal read from the track area 11 and the signal read from the guard band area 12 do not have a DC component. However, the intensity of the signal read from the track area 11 is larger than the intensity of the signal read from the guard band area 12. Therefore, the track area 11 and the guard band area 12 can be clearly identified by determining the signal strength.

  Next, consider a case where the magnetic recording medium according to the first embodiment is initialized (DC erasure) with a DC magnetic field. A magnetic field perpendicular to the substrate surface and larger than the holding force of the magnetic metal grains in the magnetic recording layer 5 is applied to the magnetic recording medium. Thereby, as shown in FIG. 4C, the magnetic recording layer 5 in the track region 11 is perpendicularly magnetized uniformly, for example, upward. At this time, the magnetic recording layer 5 in the guard band region 12 is hardly magnetized in the vertical direction, and the magnetization direction in the in-plane direction is random.

  The signal read from the track area 11 is a DC signal having a certain magnitude. A signal read from the guard band region 12 does not have a DC component. Therefore, the track area 11 and the guard band area 12 can be clearly identified by determining the DC component of the read signal.

  In the magnetic recording medium according to the first embodiment, sector servo information is written in the track area 11. In a magnetic recording medium having a structure in which sector servo information is written in areas other than the track area, a complicated read head for reading servo information is required. In the first embodiment, normal data and servo information can be read by one read head. For this reason, the structure of the read head can be simplified.

  In the first embodiment, the magnetic recording layer 5 has a granular structure in which CoCrPt magnetic metal particles are dispersed in a silicon oxide medium, and the upper orientation control layer 4 is formed of Ru or a Ru alloy. As the magnetic metal grain material in the magnetic recording layer 5, another magnetic material having a hexagonal close-packed crystal structure may be used. Examples of such a magnetic material include CoCrPtB and CoCrPtTa. In addition to Ru or Ru alloy, a nonmagnetic material having a hexagonal close-packed crystal structure can be used as the material of the upper orientation control layer 4. Examples of such materials include Pt, Pd, Rh, Re, and alloys containing these metals.

  Further, as a material for the soft magnetic layer 9 and the backing layer 2, a soft magnetic material other than CoNiFeB may be used. Examples of soft magnetic materials suitable for the soft magnetic layer 9 and the backing layer 2 include CoZrNb, CoZrTa, and NiFe. The lower layer 7 and the upper layer 8 of the lower alignment control layer 3 in the guard band region 12 have a property of preferentially orienting the c-axis of the material of the upper alignment control layer 4 in the in-plane direction other than AlCr and Cr. You may form with a magnetic material. As such a material, a nonmagnetic material whose crystal lattice type is a body-centered cubic lattice, such as AlRu, can be cited.

Next, a magnetic recording medium according to the second embodiment will be described with reference to FIGS.
FIG. 5 shows a sectional view of a magnetic recording medium according to the second embodiment. The horizontal direction (X direction) in FIG. 5 corresponds to the track width direction (radial direction), and the direction perpendicular to the paper surface (Y direction) corresponds to the track length direction (circumferential direction). Hereinafter, the description will be continued by paying attention to differences from the magnetic recording medium according to the first embodiment shown in FIG.

  In the first embodiment, the backing layer 2 is formed of a single layer made of a soft magnetic material. In the second embodiment, the guard band region 12 is formed of only the first backing layer 30, and the track region 11 has a two-layer structure of the first backing layer 30 and the second backing layer 31. A groove corresponding to the track region 11 is formed on the upper surface of the first backing layer 30. The second backing layer 31 is filled in the groove. The upper surface of the first backing layer 30 in the guard band region 12 and the upper surface of the second backing layer 31 in the track region 11 do not necessarily have to be positioned at the same height.

  The first backing layer 30 and the second backing layer 31 are both made of a soft magnetic material, but the first backing layer 30 is made of a material having a lower magnetic permeability than the second backing layer 31. For example, the first backing layer 30 is made of NiP, and the second backing layer 31 is made of CoNiFeB. The thickness of the first backing layer 30 in the guard band region 12 is, for example, about 150 nm, and the thickness of the second backing layer 31 is, for example, about 150 nm.

  A lower orientation control layer 3 is disposed on the backing layer 2. The track lower orientation control layer 3 </ b> T disposed in the track region 11 has a two-layer structure of a lower layer 35 and an upper layer 36. The guard band lower alignment control layer 3 </ b> G disposed in the guard band region 12 has a two-layer structure of a lower layer 32 and an upper layer 33.

  The lower layer 32 and the upper layer 33 of the guard band lower alignment control layer 3G are formed of the same material as the middle layer 7 and the upper layer 8 of the lower alignment control layer 3 of the guard band region 12 in the first embodiment, respectively. The thicknesses of the lower layer 32 and the upper layer 33 are equal to the thicknesses of the middle layer 7 and the upper layer 8 of the first embodiment, respectively.

  The lower layer 35 of the lower alignment control layer 3T for tracks is formed of Ta, C, Mo, Ti, W, Re, Os, or Hf. The upper layer 36 is made of a nonmagnetic material having a crystal lattice shape of face-centered cubic lattice, for example, NiFe. The upper surface 33 of the guard layer lower alignment control layer 3G and the upper surface of the track upper alignment control layer 3T have the same height, and the upper surface of the lower alignment control layer 3 is flat. It has become.

On the lower orientation control layer 3, an upper orientation control layer 4 and a magnetic recording layer 5 are laminated in the same manner as the magnetic recording medium according to the first embodiment.
Hereinafter, a method for manufacturing a magnetic recording medium according to the second embodiment will be described with reference to FIGS.

  As shown in FIG. 6A, a first backing layer 30 made of a soft magnetic material such as NiP is formed on a substrate 1 by sputtering. A lower layer 32 made of AlCr and an upper layer 33 made of Cr are formed on the first backing layer 30 by sputtering. When the lower layer 32 and the upper layer 33 are formed, it is preferable to heat the substrate to about 150 to 200 ° C. in order to promote crystallization.

  As shown in FIG. 6B, a resist pattern 40 is formed in the guard band region 12 by applying a resist made of PMMA or the like on the upper layer 33 and patterning it. The resist patterning can be performed, for example, by electron beam drawing or imprinting. The thickness of the resist pattern 40 is, for example, 150 nm.

  As shown in FIG. 6C, using the resist pattern 40 as an etching mask, etching is performed halfway through the first backing layer 30 to form a groove 41. For this etching, reactive ion etching (RIE) or focused ion beam (FIB) is used. The depth from the upper surface of the first backing layer 30 to the bottom surface of the groove 41 is, for example, 150 nm. Under the resist pattern 40, the guard band lower alignment control layer 3 </ b> G composed of the lower layer 32 and the upper layer 33 remains.

  As shown in FIG. 6D, the second backing layer 31 made of CoNiFeB or the like, the lower layer 35 of the track lower orientation control layer 3T, and the upper layer 36 are sequentially deposited on the bottom surface of the groove 41. The second backing layer 31 is formed by, for example, plating or sputtering. The lower layer 35 and the upper layer 36 are formed by sputtering. Also on the resist pattern 40, three layers 31a, 35a, and 36a made of the same material as the second backing layer 31, the lower layer 35, and the upper layer 36 are deposited. At this stage, it is not necessary to align the height of the upper surface of the upper layer 36 with the height of the upper surface of the upper layer 33 of the guard band lower alignment control layer 3G.

As shown in FIG. 6E, the resist pattern 40 is removed (lifted off) together with the layer deposited thereon.
As shown in FIG. 6F, the surface is planarized. This planarization can be performed, for example, by chemical mechanical polishing (CMP), etch back by ion etching, or the like. As shown in FIG. 5, the upper orientation control layer 4 and the magnetic recording layer 5 are formed.

Also in the second embodiment, in the guard band region 12, the c-axis of the crystal forming the upper orientation control layer 4 and the magnetic recording layer 5 is preferentially oriented in the in-plane direction.
Further, by disposing the lower layer 35 made of Ta or the like in the track region 11, the orientation and crystal grain size of the upper layer 36 such as NiFe disposed thereon can be suitably controlled. For example, the (111) surface of NiFe can be aligned in a direction parallel to the substrate surface. Thereby, the c-axis orientation of the upper orientation control layer 4 and the magnetic recording layer 5 can be enhanced.

  A second backing layer 31 having a higher magnetic permeability than the first backing layer 30 disposed in the guard band region 12 is disposed in the track region 11. For this reason, the magnetic flux concentrates on the track region 11 and the leakage magnetic flux can be reduced. In the step of FIG. 6C, the bottom surface of the groove 41 may be made coincident with the upper surface of the first backing layer 30, and the formation of the second backing layer 31 may be omitted.

  FIG. 7 is a plan view of a magnetic recording apparatus using the magnetic recording medium according to the first or second embodiment. The housing 50 defines a flat rectangular parallelepiped internal space. One or more magnetic disks 51 are accommodated in this internal space. The magnetic disk 51 has the same structure as the magnetic recording medium according to the first or second embodiment. The magnetic disk 51 is mounted on the rotation shaft of the spindle motor 52. The spindle motor 52 rotates the magnetic disk 51 at a high speed, for example, at a rotational speed of 7200 rpm or 10,000 rpm.

  A head actuator 55 is mounted on a support shaft 53 that extends in a direction parallel to the rotation axis of the spindle motor 52. The head actuator 55 includes an arm 56 and a suspension 57. The arm 56 is supported by a support shaft 53 so as to be swingable in a direction parallel to the surface of the magnetic disk 51. The suspension 57 is attached to the tip of the arm 56 and extends forward from the arm 56. A flying head slider 58 is attached to the tip of the suspension 58.

By using the magnetic recording medium according to the first or second embodiment for the magnetic disk 51, a magnetic recording apparatus that is less susceptible to magnetic interference from adjacent tracks can be obtained.
Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

The invention shown in the following supplementary notes is derived from the above embodiments.
(Appendix 1)
A substrate made of a non-magnetic material;
A magnetic recording layer formed on the substrate, wherein a plurality of track areas in which data is recorded and a guard band area disposed between adjacent track areas are defined. The magnetic recording layer in the region exhibits magnetic anisotropy that is more easily magnetized in the vertical direction than in the in-plane direction, and the magnetic recording layer in the guard band region has a magnetic anisotropy that is more easily magnetized in the in-plane direction than in the vertical direction. A magnetic recording medium having a magnetic recording layer exhibiting directionality. (1)
(Appendix 2)
A substrate made of a non-magnetic material;
A magnetic recording layer disposed on the substrate and including a magnetic material having a hexagonal close-packed crystal structure, and disposed between a plurality of track regions in which data is recorded and track regions adjacent to each other A guard band region is defined, and in the track region, the c-axis of the magnetic material in the magnetic recording layer is preferentially oriented in a direction perpendicular to the substrate surface, and in the guard band region, and a magnetic recording layer having a c-axis preferentially oriented in a direction parallel to the substrate surface. (2)
(Appendix 3)
And an upper alignment control layer disposed between the substrate and the magnetic recording layer, the upper alignment control layer being formed of a nonmagnetic material having a hexagonal close-packed crystal structure, and the track region In the region corresponding to, the c-axis is preferentially oriented in the direction perpendicular to the substrate surface, and in the region corresponding to the guard band region, the c-axis is preferentially oriented in the direction parallel to the substrate surface. The magnetic recording medium according to appendix 1 or 2.

(Appendix 4)
The magnetic recording medium according to appendix 3, wherein the upper orientation control layer is made of Ru or an alloy containing Ru.

(Appendix 5)
And a lower alignment control layer disposed between the upper alignment control layer and the substrate. The lower alignment control layer corresponding to the track region is formed of a soft magnetic material, and the guard The magnetic recording medium according to appendix 3 or 4, wherein the lower orientation control layer in the region corresponding to the band region is formed of a nonmagnetic material.

(Appendix 6)
The magnetic recording medium according to appendix 5, further comprising a backing layer disposed between the lower orientation control layer and the substrate and made of a soft magnetic material.

(Appendix 7)
A plurality of track areas where data is recorded and a guard band area disposed between adjacent track areas are defined, and the magnetic recording layer in the track area is perpendicular to the in-plane direction. Providing a magnetic recording medium that exhibits magnetic anisotropy that is easily magnetized, and the magnetic recording layer in the guard band region exhibits magnetic anisotropy that is more easily magnetized in the in-plane direction than in the vertical direction;
A step of magnetically initializing the magnetic recording layer by applying a magnetic field that is larger than the coercive force of the magnetic material forming the magnetic recording layer and is perpendicular to the magnetic recording layer. A method for initializing a magnetic recording medium. (3)
(Appendix 8)
(A) An underlayer made of a non-magnetic material on a guard band region of a substrate in which a plurality of track regions and a guard band region disposed between adjacent track regions are defined on the surface Forming a step;
(B) forming a soft magnetic member by filling a track region between the underlayers with a soft magnetic material until an upper surface is higher than an upper surface of the underlayer;
(C) depositing a nonmagnetic material on the underlayer and the soft magnetic member to form an upper layer;
(D) planarizing the surface so that the soft magnetic member is exposed in the track region and the upper layer remains in the guard band region;
(E) forming an upper orientation control layer made of a nonmagnetic material on the planarized surface;
(F) forming a magnetic recording layer containing a magnetic material on the upper orientation control layer. (4)
(Appendix 9)
The crystal structure of the nonmagnetic material forming the upper orientation control layer and the magnetic material included in the magnetic recording layer is a hexagonal close-packed structure, and the soft magnetic member is exposed among the flattened surface in the step d. The region is preferentially oriented so that the c-axis of the nonmagnetic material forming the orientation control layer is perpendicular to the substrate surface, and the region where the upper layer is exposed is the c-axis of the nonmagnetic material forming the orientation control layer 9. The method for manufacturing a magnetic recording medium according to appendix 8, wherein the magnetic recording medium has a property of preferentially orienting so that is parallel to the substrate surface.

(Appendix 10)
The method of manufacturing a magnetic recording medium according to appendix 9, wherein in the step f, the magnetic recording layer is formed under a condition that the magnetic material of the magnetic recording layer takes over the crystal orientation state of the underlying surface.

(Appendix 11)
(P) A lower alignment control layer for a guard band made of a nonmagnetic material on a substrate having a plurality of track regions and a guard band region disposed between adjacent track regions on the surface. Forming a step;
(Q) forming a groove reaching at least the bottom surface of the lower alignment control layer for the guard band in the track region;
(R) filling the groove with a soft magnetic material to form a lower alignment control layer for tracks;
(S) forming an upper alignment control layer made of a nonmagnetic material on the guard band lower alignment control layer and the track lower alignment control layer;
And (t) forming a magnetic recording layer containing a magnetic material on the upper alignment control layer. (5)
(Appendix 12)
The crystal structure of the nonmagnetic material forming the upper alignment control layer and the magnetic material included in the magnetic recording layer is a hexagonal close-packed structure, and the surface of the lower alignment control layer for tracks is formed of the upper alignment control layer. The c-axis of the non-magnetic material to be formed is preferentially oriented so that the c-axis of the non-magnetic material is perpendicular to the substrate surface, and the c-axis of the non-magnetic material forming the upper orientation control layer is on the upper surface of the lower orientation control layer for the guard band The method for producing a magnetic recording medium according to appendix 11, wherein the magnetic recording medium is preferentially oriented so as to be parallel to the surface.

(Appendix 13)
13. The method of manufacturing a magnetic recording medium according to appendix 12, wherein in the step t, the magnetic recording layer is formed under a condition that the magnetic material of the magnetic recording layer takes over the crystal orientation state of the underlying surface.

1 is a partially broken perspective view of a magnetic recording medium according to a first embodiment. It is sectional drawing (the 1) of the medium in the middle of manufacture of the magnetic-recording medium by a 1st Example. FIG. 6 is a cross-sectional view (part 2) of the medium in the middle of manufacturing the magnetic recording medium according to the first embodiment. FIG. 4 is a cross-sectional view (part 3) of the medium in the middle of manufacturing the magnetic recording medium according to the first embodiment. FIG. 6 is a cross-sectional view (part 4) of the medium in the middle of manufacturing the magnetic recording medium according to the first embodiment. It is a figure which shows schematically the mode of magnetization of the magnetic recording medium in which the guard band area | region is not provided, and the magnetic flux. It is a figure which shows roughly the mode of magnetization of the magnetic recording medium by a 1st Example, and the mode of magnetic flux. It is a figure which shows the mode of magnetization of a track area when the magnetic recording medium by a 1st Example is AC erased, and a read signal waveform. It is a figure which shows the mode of magnetization of a guard band area | region when a magnetic recording medium by a 1st Example is AC erased, and a read signal waveform. It is a figure which shows the mode of magnetization of a track area when a magnetic recording medium according to the first embodiment is DC erased, and a read signal waveform. It is a partially broken perspective view of the magnetic recording medium according to the second embodiment. It is sectional drawing (the 1) of the medium in the middle of manufacture of the magnetic-recording medium by a 2nd Example. It is sectional drawing (the 2) of the medium in the middle of manufacture of the magnetic-recording medium by a 2nd Example. It is sectional drawing (the 3) of the medium in the middle of manufacture of the magnetic-recording medium by a 2nd Example. It is sectional drawing (the 4) of the medium in the middle of manufacture of the magnetic-recording medium by a 2nd Example. It is sectional drawing (the 5) of the medium in the middle of manufacture of the magnetic-recording medium by a 2nd Example. It is sectional drawing (the 6) of the medium in the middle of manufacture of the magnetic-recording medium by a 2nd Example. It is a top view of the magnetic-recording apparatus using the magnetic-recording medium by a 1st or 2nd Example. It is a partially broken perspective view of the conventional magnetic recording medium. It is a partially broken perspective view of the conventional magnetic recording medium. It is sectional drawing of the conventional magnetic recording medium.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Backing layer 3 Lower orientation control layer 4 Upper orientation control layer 5 Magnetic recording layer 6 Underlayer 7 Middle layer 8 Lower layer 9 Soft magnetic layer 11 Track region 12 Guard band region 20 Read head 30 First backing layer 31 Second backing Layer 32 Lower layer for guard band lower alignment control layer 33 Upper layer for guard band lower alignment control layer 35 Lower layer for track lower alignment control layer 36 Upper layer for track lower alignment control layer 40 Resist pattern 41 Groove 50 Housing Body 51 Magnetic disk 52 Spindle motor 53 Support shaft 55 Head actuator 56 Arm 57 Suspension 58 Flying head slider

Claims (5)

A substrate made of a non-magnetic material;
A magnetic recording layer formed on the substrate, wherein a plurality of track areas in which data is recorded and a guard band area disposed between adjacent track areas are defined. The magnetic recording layer in the region exhibits magnetic anisotropy that is more easily magnetized in the vertical direction than in the in-plane direction, and the magnetic recording layer in the guard band region has a magnetic anisotropy that is more easily magnetized in the in-plane direction than in the vertical direction. A magnetic recording medium having a magnetic recording layer exhibiting directionality. A substrate made of a non-magnetic material;
A magnetic recording layer disposed on the substrate and including a magnetic material having a hexagonal close-packed crystal structure, and disposed between a plurality of track regions in which data is recorded and track regions adjacent to each other A guard band region is defined, and in the track region, the c-axis of the magnetic material in the magnetic recording layer is preferentially oriented in a direction perpendicular to the substrate surface, and in the guard band region, and a magnetic recording layer having a c-axis preferentially oriented in a direction parallel to the substrate surface. A plurality of track areas where data is recorded and a guard band area disposed between adjacent track areas are defined, and the magnetic recording layer in the track area is perpendicular to the in-plane direction. Providing a magnetic recording medium that exhibits magnetic anisotropy that is easily magnetized, and the magnetic recording layer in the guard band region exhibits magnetic anisotropy that is more easily magnetized in the in-plane direction than in the vertical direction;
A step of magnetically initializing the magnetic recording layer by applying a magnetic field that is larger than the coercive force of the magnetic material forming the magnetic recording layer and is perpendicular to the magnetic recording layer. A method for initializing a magnetic recording medium. (A) An underlayer made of a non-magnetic material on a guard band region of a substrate in which a plurality of track regions and a guard band region disposed between adjacent track regions are defined on the surface Forming a step;
(B) forming a soft magnetic member by filling a track region between the underlayers with a soft magnetic material until an upper surface is higher than an upper surface of the underlayer;
(C) depositing a nonmagnetic material on the underlayer and the soft magnetic member to form an upper layer;
(D) planarizing the surface so that the soft magnetic member is exposed in the track region and the upper layer remains in the guard band region;
(E) forming an upper orientation control layer made of a nonmagnetic material on the planarized surface;
(F) forming a magnetic recording layer containing a magnetic material on the upper orientation control layer. (P) A lower alignment control layer for a guard band made of a nonmagnetic material on a substrate having a plurality of track regions and a guard band region disposed between adjacent track regions on the surface. Forming a step;
(Q) forming a groove reaching at least the bottom surface of the lower alignment control layer for the guard band in the track region;
(R) filling the groove with a soft magnetic material to form a lower alignment control layer for tracks;
(S) forming an upper alignment control layer made of a nonmagnetic material on the guard band lower alignment control layer and the track lower alignment control layer;
And (t) forming a magnetic recording layer containing a magnetic material on the upper alignment control layer.

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