JP2010129142A - Storage medium and storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storage medium wherein recording density is enhanced by suppressing side erasure and to provide a storage device. <P>SOLUTION: In each magnetic dot 64, an outer end of a soft magnetic body 68 is regulated on a center line 63 side of a recording track 61 than an outer end of a hard magnetic body 67. Magnetic exchange coupling is attained between the hard magnetic body 67 and the soft magnetic body 68. As a result, when a prescribed recording magnetic field acts on the soft magnetic body 68 on the center line 63 side, magnetization is easily turned in a prescribed direction in the soft magnetic body 68 and the hard magnetic body 67. Meanwhile, the soft magnetic body 68 is not disposed on the hard magnetic body 67 on an outer side adjacent to a border line 66. Magnetization direction is hardly changed in the hard magnetic body 67 even when a recording magnetic field acts on the hard magnetic body 67. Even when a recording magnetic field acts on recording tracks 61 adjacent via the border line 66, generation of side erasure is suppressed. As a result, bit pitch between magnetic dots 64 is made narrower than ever in a cross track direction. Recording density is enhanced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a storage medium such as a bit patterned medium.

In a magnetic storage medium such as a bit patterned medium, magnetic dots are arranged in an arbitrary pattern in a nonmagnetic material for each recording track. Each magnetic dot is formed of a hard magnetic material and a soft magnetic material disposed on the hard magnetic material. Exchange coupling is realized between the hard magnetic material and the soft magnetic material. As a result, the magnetization of the magnetic dots can be reversed with a relatively small recording magnetic field.
JP 2008-16072 A JP 2007-250047 A

  In increasing the recording density, the pitch between adjacent recording tracks is narrowed. As a result, the recording magnetic field of the write head acts on the recording track adjacent to the recording track to be written. As described above, since magnetization can be reversed with a relatively small recording magnetic field, magnetic information is written on a recording track that is not a write target. Side erase will occur.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a storage medium and a storage device capable of improving the recording density by suppressing side erasure.

  To achieve the above object, a storage medium includes a substrate, a plurality of subtracks extending along a downtrack direction on the substrate to establish a single recording track, and a downtrack within each subtrack. Boundary line between the recording track adjacent to the recording track in each recording track, and a magnetic dot formed from a hard magnetic material and a soft magnetic material arranged on the hard magnetic material In the subtrack extending along the magnetic track, the soft magnetic body of the magnetic dot defines an outer end on the center line side of the recording track rather than an outer end of the hard magnetic body defined on the boundary line side. It is characterized by.

  According to such a storage medium, on the hard magnetic material of each magnetic dot, the soft magnetic material defines the outer end on the center line side of the recording track from the outer end of the hard magnetic material. In each magnetic dot, magnetic exchange coupling is realized between the hard magnetic material and the soft magnetic material. As a result, if a predetermined recording magnetic field acts on the soft magnetic material on the center line side in the recording track, the magnetization is easily directed in a predetermined direction by the soft magnetic material and the hard magnetic material. On the other hand, in each magnetic dot, no soft magnetic material is disposed on the hard magnetic material outside the boundary line. Even if a recording magnetic field acts on the hard magnetic material, the magnetization direction hardly changes in the hard magnetic material. Therefore, even if a recording magnetic field acts on adjacent recording tracks across the boundary line, the occurrence of side erasure is suppressed. As a result, the bit pitch between the magnetic dots in the cross track direction is narrowed more than ever. The recording density is improved. In addition, since the volume is ensured as before in the hard magnetic material, the magnetic dots can sufficiently withstand the thermal fluctuation.

  The storage medium includes a substrate, a plurality of sub-tracks extending along the down-track direction on the substrate to establish one recording track, and arranged in the down-track direction within each of the sub-tracks. And a magnetic dot formed from a soft magnetic material disposed on the hard magnetic material, and the subtrack extending along a boundary line with the recording track adjacent to the recording track in each recording track. The soft magnetic material of the magnetic dots is characterized in that the film thickness decreases as the distance from the center line of the recording track increases toward the boundary line.

  According to such a storage medium, the soft magnetic material has a relatively large film thickness on the center line side of the recording track. If a predetermined recording magnetic field acts on the soft magnetic material on the center line side, the magnetization is easily directed in a predetermined direction by the hard magnetic material. Moreover, the soft magnetic material has a relatively small film thickness on the outside adjacent to the boundary line. Even if a recording magnetic field acts, the magnetization direction is hard to change due to the hard magnetic material. Even if the recording magnetic field acts on the recording tracks adjacent to each other across the boundary line, the occurrence of side erasure is suppressed. The recording density is improved. In addition, since the volume is ensured as before in the hard magnetic material, the magnetic dots can sufficiently withstand the thermal fluctuation.

  As described above, the storage medium and the storage device can improve the recording density by suppressing the side erase.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 schematically shows an internal structure of a hard disk drive (HDD) 11 as a specific example of a storage device according to the present invention. The HDD 11 includes a housing, that is, a housing 12. The housing 12 includes a box-shaped base 13 and a cover (not shown). The base 13 defines, for example, a flat rectangular parallelepiped internal space, that is, an accommodation space. The base 13 may be formed from a metal material such as Al (aluminum) based on casting. The cover is coupled to the opening of the base 13. The accommodation space is sealed between the cover and the base 13. The cover may be formed from a single plate material based on press working, for example.

  In the accommodation space, one or more magnetic disks 14 as storage media are accommodated. The magnetic disk 14 is mounted on the drive shaft of the spindle motor 15. The spindle motor 15 can rotate the magnetic disk 14 at a high speed such as 4200 rpm, 5400 rpm, 7200 rpm, 10000 rpm, and 15000 rpm. Here, for example, the magnetic disk 14 is configured as a perpendicular magnetic recording disk. That is, in the recording magnetic layer on the magnetic disk 14, the easy axis of magnetization is set in the vertical direction perpendicular to the surface of the magnetic disk 14.

  A carriage 16 is further accommodated in the accommodation space. The carriage 16 includes a carriage block 17. The carriage block 17 is rotatably connected to a support shaft 18 extending in the vertical direction. A plurality of carriage arms 19 extending in the horizontal direction from the support shaft 18 are defined in the carriage block 17. The carriage block 17 may be molded from Al based on extrusion molding, for example.

  A head suspension 21 is attached to the tip of each carriage arm 19. The head suspension 21 extends forward from the tip of the carriage arm 19. A flexure is attached to the head suspension 21. A gimbal is defined in the flexure at the tip of the head suspension 21. A magnetic head slider, that is, a flying head slider 22 is mounted on the gimbal. The posture of the flying head slider 22 can be changed with respect to the head suspension 21 by the action of the gimbal. A magnetic head, that is, an electromagnetic transducer is mounted on the flying head slider 22.

  When an air flow is generated on the surface of the magnetic disk 14 based on the rotation of the magnetic disk 14, positive pressure, that is, buoyancy and negative pressure act on the flying head slider 22 by the action of the air flow. Since the buoyancy and negative pressure balance with the pressing force of the head suspension 21, the flying head slider 22 can continue to fly with relatively high rigidity during the rotation of the magnetic disk.

  For example, a power source such as a voice coil motor (VCM) 23 is connected to the carriage block 17. The carriage block 17 can rotate around the support shaft 18 by the action of the VCM 23. Based on the rotation of the carriage block 17, the swing of the carriage arm 19 and the head suspension 21 is realized. When the carriage arm 19 swings around the spindle 18 while the flying head slider 22 is flying, the flying head slider 22 can move along the radial line of the magnetic disk 14. As a result, the electromagnetic transducer on the flying head slider 22 can cross the data zone between the innermost recording track and the outermost recording track. Thus, the electromagnetic transducer on the flying head slider 22 is positioned on the target recording track.

  FIG. 2 shows a flying head slider 22 according to one specific example. The flying head slider 22 includes a base material, that is, a slider body 25 formed in a flat rectangular parallelepiped, for example. An insulating nonmagnetic film, that is, a device built-in film 26 is laminated on the air outflow side end face of the slider body 25. An electromagnetic conversion element 27 is incorporated in the element built-in film 26. Details of the electromagnetic conversion element 27 will be described later.

The slider body 25 is made of a hard nonmagnetic material such as Al ₂ O ₃ —TiC (Altic). The element built-in film 26 is made of a relatively soft insulating nonmagnetic material such as Al ₂ O ₃ (alumina). The slider body 25 faces the magnetic disk 14 at the medium facing surface, that is, the air bearing surface 28. A flat base surface 29, that is, a reference surface is defined on the air bearing surface 28. When the magnetic disk 14 rotates, an air flow 31 acts on the air bearing surface 28 from the front end to the rear end of the slider body 25.

  A single front rail 32 rising from the base surface 29 is formed on the air bearing surface 28 on the upstream side of the air flow 31, that is, on the air inflow side. The front rail 32 extends in the slider width direction along the air inflow end of the base surface 29. Similarly, a rear center rail 33 rising from the base surface 29 is formed on the air bearing surface 28 on the downstream side of the air flow 31, that is, on the air outflow side. The rear center rail 33 is disposed at the center position in the slider width direction. The rear center rail 33 reaches the element built-in film 26. A pair of left and right rear side rails 34, 34 are further formed on the air bearing surface 28. The rear side rail 34 rises from the base surface 29 along the side end of the slider body 25 on the air outflow side. The rear center rail 33 is disposed between the rear side rails 34 and 34.

  So-called air bearing surfaces (ABS) 35, 36, 37, 37 are defined on the top surfaces of the front rail 32, the rear center rail 33, and the rear side rails 34, 34. The air inflow ends of the air bearing surfaces 35, 36, and 37 are connected to the top surfaces of the front rail 32, the rear center rail 33, and the rear side rail 34 by steps. When the air flow 31 is received by the air bearing surface 28, a relatively large positive pressure, that is, buoyancy is generated on the air bearing surfaces 35, 36, and 37 by the action of the steps. Moreover, a large negative pressure is generated behind the front rail 32, that is, behind the front rail 32. The flying posture of the flying head slider 22 is established based on the balance between these buoyancy and negative pressure. The form of the flying head slider 22 is not limited to this form.

  An electromagnetic conversion element 27 is embedded in the rear center rail 33 on the air outflow side of the air bearing surface 36. The electromagnetic conversion element 27 includes, for example, a reading element and a magnetic recording head, that is, a writing element. A tunnel junction magnetoresistive effect (TuMR) element is used as the read element. In the TuMR element, the resistance change of the tunnel junction film is caused according to the direction of the magnetic field acting from the magnetic disk 14. Magnetic information, that is, binary information is read from the magnetic disk 14 based on such resistance change. A so-called single pole head is used for the writing element. The single pole head generates a recording magnetic field by the action of a thin film coil pattern. Binary information is written on the magnetic disk 14 by the action of the recording magnetic field. The electromagnetic conversion element 27 exposes the read gap of the read element and the write gap of the write element on the surface of the element built-in film 26.

  However, a hard protective film may be formed on the surface of the element built-in film 26 on the air outflow side of the air bearing surface 36. Such a hard protective film covers the read gap and the write gap exposed on the surface of the element built-in film 26. For example, a DLC (diamond-like carbon) film may be used as the protective film.

  As shown in FIG. 3, in the read element 38, a tunnel junction magnetoresistive film 42 is sandwiched between a pair of upper and lower conductive layers, that is, a lower electrode 39 and an upper electrode 41. The lower electrode 39 and the upper electrode 41 may be made of a high magnetic permeability material such as FeN (iron nitride), NiFe (nickel iron), NiFeB (nickel iron boron), or CoFeB (cobalt iron boron). Thus, the lower electrode 39 and the upper electrode 41 can function as a lower shield layer and an upper shield layer. As a result, the distance between the lower electrode 39 and the upper electrode 41 determines the magnetic recording resolution in the down-track direction of the recording track on the magnetic disk 14.

At the same time, a pair of magnetic domain control films 43 are disposed between the lower electrode 39 and the upper electrode 41. The tunnel junction magnetoresistive film 42 is disposed between the magnetic domain control films 43 along the air bearing surface 28. The magnetic domain control film 43 is made of a hard magnetic material such as CoCrPt (cobalt chromium platinum). The magnetic domain control film 43 establishes magnetization in one direction along the air bearing surface 28. An insulating film 44 is sandwiched between the magnetic domain control film 43 and the lower electrode 39 and between the magnetic domain control film 43 and the tunnel junction magnetoresistive film 42. Insulating film 44 may be formed of, for example, _Al 2 _{O 3.} The magnetic domain control film 43 is insulated from the lower electrode 39 and the tunnel junction magnetoresistive film 42. Therefore, even if the magnetic domain control film 43 has conductivity, conduction is established between the upper electrode 41 and the lower electrode 39 only by the tunnel junction magnetoresistive film 42.

  The writing element 45, that is, the single magnetic pole head, includes a main magnetic pole 46 and an auxiliary magnetic pole 47 that expose the front end surface on the surface of the rear center rail 33, that is, the air bearing surface 28. A trailing shield 48 is defined at the leading end of the auxiliary magnetic pole 47 on the air bearing surface 28. The trailing shield 48 is opposed to the main magnetic pole 46. The main magnetic pole 46, the auxiliary magnetic pole 47, and the trailing shield 48 are made of a magnetic material such as FeN, NiFe, NiFeB, or CoFeB. Referring also to FIG. 4, the rear end of the auxiliary magnetic pole 47 is connected to the main magnetic pole 46 by a magnetic coupling piece 49. A magnetic coil, that is, a thin film coil pattern 51 is formed around the magnetic coupling piece 49. Thus, the main magnetic pole 46, the auxiliary magnetic pole 47, the trailing shield 48, and the magnetic coupling piece 49 form a magnetic core that penetrates the center position of the thin film coil pattern 51. 4 is a cross-sectional view taken along line 4-4 of FIG.

  FIG. 5 schematically shows the structure of the magnetic disk 14 according to the first embodiment of the present invention. This magnetic disk 14 constitutes a bit patterned medium. A plurality of recording tracks 61, 61,... Extend on the front and back surfaces of the magnetic disk 14 along the circumferential direction of the magnetic disk 14, that is, the down track direction. The recording track 61 is formed concentrically. As shown in FIG. 6, each recording track 61 is established from a plurality of sub-tracks 62 extending in the down track direction. Here, in each recording track 61, two sub-tracks 62 extend in the down track direction. As a result, the sub-tracks 62 extend along the center line 63 with the center line 63 of the recording track 61 interposed therebetween.

In each sub-track 62, a plurality of magnetic dots 64 are arranged in the down-track direction at a predetermined interval. Here, the magnetic dots 64 are arranged at equal intervals. One magnetic bit is established by one magnetic dot 64. In each magnetic dot 64, upward magnetization or downward magnetization is established in a perpendicular direction perpendicular to the surface of the magnetic disk 14. In this way, binary information is recorded on each magnetic dot 64. The magnetic dots 64 are magnetically separated by a nonmagnetic material 65. The nonmagnetic material 65 is made of a nonmagnetic material such as SiO ₂ (silicon oxide) or Al ₂ O ₃ .

  The magnetic dots 64 are alternately arranged along the center line 63 between the subtracks 62 and 62 adjacent to each other. Here, the center point of the magnetic dot 64 of the adjacent subtrack 62 is arranged on the radial line passing through the intermediate position between the center points of the magnetic dots 64 adjacent to each other in the downtrack direction on an arbitrary subtrack 62. Is done. The recording tracks 61 and 61 extend in parallel along a boundary line 66. The boundary line 66 extends in the down track direction in parallel with the center line 63 of the recording track 61.

  Each magnetic dot 64 is formed from a laminated body of a hard magnetic body 67 and a soft magnetic body 68 disposed on the hard magnetic body 67. The hard magnetic body 67 is made of a hard magnetic material such as CoCrPt. The soft magnetic body 68 is made of a soft magnetic material such as NiFe. In the sub-track 62 arranged along the boundary line 66 in each recording track 61, the soft magnetic body 68 has an outer end closer to the center line 63 than the outer end of the hard magnetic body 67 defined on the boundary line 66 side. Is specified. The inner end of the soft magnetic body 68 is aligned with the inner end of the hard magnetic body 67. Here, the outer side on the magnetic disk 14 is defined in a direction away from the center line 63 of the recording track 61 in the cross track direction toward the inner circumference side and the outer circumference side.

  Referring also to FIG. 7, the bit width Bw of the hard magnetic body 67 defined in the cross track direction is set to about 44 nm, for example. The bit length BL of the hard magnetic body 67 defined in the down track direction is set to about 20 nm, for example. The film thickness of the hard magnetic body 67 is set to about 10 nm, for example. The bit width Bw of the soft magnetic body 68 is set to about 30 nm. The bit length BL of the soft magnetic body 68 is set to about 20 nm. The film thickness of the soft magnetic body 68 is set to about 5 nm, for example. The bit pitch between the magnetic dots 64 adjacent to each other in the cross track direction is set to about 64 nm. The bit pitch between the magnetic dots 64 adjacent to each other in the down track direction is set to about 40 nm.

  FIG. 8 shows a cross-sectional structure of the magnetic disk 14 according to the first embodiment of the present invention. The magnetic disk 14 includes a substrate 71. The substrate 71 is formed from, for example, a glass substrate. A backing layer 72 spreads on the surface of the substrate 71. The backing layer 72 is made of a soft magnetic material such as a FeTaC (iron carbide tantalum) film NiFe film. In the backing layer 72, an easy axis of magnetization is established in an in-plane direction defined parallel to the surface of the substrate 71. The film thickness of the backing layer 72 is set to about 50 nm, for example. A nonmagnetic intermediate layer 73 spreads on the surface of the backing layer 72. The nonmagnetic intermediate layer 73 is made of a nonmagnetic material such as Ta (tantalum) or Ru (ruthenium). The film thickness of the nonmagnetic intermediate layer 73 is set to about 5 nm, for example.

  A recording magnetic layer 74 spreads on the surface of the nonmagnetic intermediate layer 73. The magnetic dots 64 and the nonmagnetic material 65 described above are formed on the recording magnetic layer 74. A hard magnetic body 67 is disposed on the surface of the nonmagnetic intermediate layer 73. A non-magnetic material 65 covers the hard magnetic material 67 outside the soft magnetic material 68. A flat surface is defined by the surface of the soft magnetic body 68 and the surface of the non-magnetic body 65. In each magnetic dot 64, an easy axis of magnetization is established in a direction perpendicular to the surface of the substrate 71. The surface of the recording magnetic layer 74 is covered with a protective film 75 such as a diamond-like carbon (DLC) film and a lubricating film 76 such as a perfluoropolyether (PFPE) film. The film thickness of the protective film 75 is set to about 3 nm, for example. The film thickness of the lubricating film 76 is set to about 1 nm, for example.

  Now, when the flying head slider 22 faces the surface of the magnetic disk 14 at the flying surface 28, the write element 45 follows the center line 63 on one recording track 61 as shown in FIG. When the center line of the writing element 45 is positioned on the center line 63, on-track is realized. In the writing element 45, the core width at the trailing end of the main magnetic pole 46 is set to about the track width of the recording track 61. On the other hand, in the read element 38, the tunnel junction magnetoresistive film 42 is disposed on both the subtracks 62 and 62, that is, the recording track 61. Here, the core width of the tunnel junction magnetoresistive film 42 is set to about the track width of the recording track 61.

  When writing binary information, the recording magnetic field leaks from the trailing end of the main magnetic pole 46 toward the magnetic disk 14. The leaking recording magnetic field acts on the recording magnetic layer 74 by the magnetic dots 64. A recording magnetic field is induced in the recording magnetic layer 74 in a direction perpendicular to the surface of the recording magnetic layer 74. The recording magnetic field circulates from the backing layer 72 to the trailing shield 48 of the writing element 45. Based on the circulation of the recording magnetic field, upward magnetization or downward magnetization is established for each magnetic dot 64 in the recording magnetic layer 74. Since the magnetic dots 64 are alternately arranged along the center line 63, the writing element 45 can individually write binary information to each magnetic dot 64 in order.

  In each magnetic dot 64, magnetic exchange coupling is realized between the hard magnetic body 67 and the soft magnetic body 68. As a result, when a recording magnetic field acts on the soft magnetic body 68 from the trailing end of the main magnetic pole 46 in writing binary information, the magnetization direction of the soft magnetic body 68 is easily changed to a predetermined direction according to the circulation of the recording magnetic field. Directed. As a result, the magnetization direction of the hard magnetic body 67 immediately below the soft magnetic body 68 is easily directed to a predetermined direction. In the hard magnetic body 67, magnetization is partially established in a predetermined direction. With the establishment of such a partial magnetization direction, the magnetization of the hard magnetic body 67 is directed in a predetermined direction throughout the entire area. Thus, magnetization in one direction is established at each magnetic dot 64. As a result, binary information is written to the magnetic dots 64.

  On the other hand, when reading binary information, the magnetic field leaking from the magnetic dots 64 of the recording magnetic layer 74 acts on the tunnel junction film of the tunnel junction magnetoresistive film 42. The resistance change of the tunnel junction film is caused according to the direction of the magnetic field acting from the magnetic disk 14. Based on such resistance change, binary information is read from the magnetic disk 14. As described above, since the magnetic dots 64 are alternately arranged along the center line 63, the reading element 38 can individually read binary information from each magnetic dot 64 in order.

  According to the HDD 11 as described above, on the hard magnetic body 67 of each magnetic dot 64, the soft magnetic body 68 defines the outer end on the center line 63 side with respect to the outer end of the hard magnetic body 67. Each magnetic dot 64 realizes magnetic exchange coupling between the hard magnetic body 67 and the soft magnetic body 68. As a result, in the recording track 61, if a predetermined recording magnetic field acts on the soft magnetic body 68 on the center line 63 side, the magnetization is easily directed in a predetermined direction by the soft magnetic body 68 and the hard magnetic body 67. Therefore, it is sufficient for the main magnetic pole 46 of the writing element 45 to apply a recording magnetic field to the magnetic dots 64 along the central axis 63 in each recording track 61.

  On the other hand, in each magnetic dot 64, the soft magnetic body 68 is not disposed on the hard magnetic body 67 outside the boundary line 66. Even if a recording magnetic field acts on the hard magnetic body 67, the direction of magnetization hardly changes in the hard magnetic body 67. Therefore, even if a recording magnetic field acts on the recording tracks 61 adjacent to each other with the boundary line 66 interposed therebetween, the occurrence of side erase is suppressed. As a result, the bit pitch between the magnetic dots 64 and 64 in the cross track direction is narrowed more than ever. In the HDD 11, the recording density is improved. In addition, since the hard magnetic material 67 has a volume as before, the magnetic dots 64 can sufficiently withstand thermal fluctuations.

  In the HDD 11 as described above, the soft magnetic body 68 is placed on the hard magnetic body 67 with an area where the magnetization direction can be established in a predetermined direction by the hard magnetic body 67 based on the recording magnetic field acting on the soft magnetic body 68. It only needs to spread. Therefore, the contour of the soft magnetic body 68 on the hard magnetic body 67 is not limited to the above-described form. For example, the inner end of the soft magnetic body 68 may not necessarily coincide with the inner end of the hard magnetic body 67. For example, the inner end of the soft magnetic body 68 may be defined outside the inner end of the hard magnetic body 67 from the center line 63 in the cross track direction. In addition, for example, the side end of the soft magnetic body 68 defined in the down track direction may not necessarily coincide with the side end of the hard magnetic body 67 defined in the Dowton rack direction.

  Next, a method for manufacturing the magnetic disk 14 will be described. First, a substrate 71 is prepared. As shown in FIG. 10, a backing layer 72 and a nonmagnetic intermediate layer 73 are formed on the surface of the substrate 71 with a predetermined film thickness by sputtering, for example. After the formation, a hard magnetic continuous film 81 is formed on the surface of the nonmagnetic intermediate layer 73 with a predetermined film thickness. For example, sputtering is performed. Thereafter, for example, an ultraviolet curable resin material 82 is applied to the surface of the hard magnetic continuous film 81.

  As shown in FIG. 11, the surface of the first mold 83 is superimposed on the resin material 82. The first mold 83 is formed from an ultraviolet light transmissive material. A predetermined uneven pattern is formed on the surface of the first mold 83. Here, a recess 83 a is formed on the surface of the first mold 83 at a position corresponding to the position of the hard magnetic body 67 described above. At this time, ultraviolet rays are irradiated toward the surface of the substrate 71. The resin material 82 is cured. The first mold 83 is peeled off from the surface of the resin material 82. In this way, a predetermined pattern is transferred to the resin material 82 as shown in FIG.

  Thereafter, reactive ion etching (RIE) is performed on the surface of the resin material 82. As a result, as shown in FIG. 13, the excess resin material 82 remaining on the surface of the hard magnetic continuous film 81 is removed. Thus, the resin material 82 forms a predetermined pattern on the surface of the nonmagnetic intermediate layer 73. Dry etching is performed on the surface of the hard magnetic continuous film 81. As a result, as shown in FIG. 14, the hard magnetic continuous film 81 is scraped around the resin material 82. Thus, the hard magnetic body 67 is formed immediately below the resin material 82. The resin material 82 is removed.

  As shown in FIG. 15, a soft magnetic film 84 having a predetermined thickness is formed on the surface of the nonmagnetic intermediate layer 73 based on sputtering. The soft magnetic film 84 covers the hard magnetic body 67 on the surface of the nonmagnetic intermediate layer 73. Thereafter, as shown in FIG. 16, for example, an ultraviolet curable resin material 85 is applied to the surface of the soft magnetic film 84. As shown in FIG. 17, the surface of the second mold 86 is overlaid on the resin material 85. The second mold 86 is made of an ultraviolet light transmissive material. A predetermined uneven pattern is formed on the surface of the second mold 86. Here, a recess 86 a corresponding to the position of the hard magnetic body 67 and a recess 86 b corresponding to the position of the soft magnetic body 68 are formed on the surface of the first mold 85.

  At this time, the surface of the substrate 71 is irradiated with ultraviolet rays. The resin material 85 is cured. The second mold 86 is peeled off from the surface of the resin material 85. Thus, a predetermined pattern is transferred to the resin material 85 as shown in FIG. Thereafter, as described above, reactive ion etching (RIE) is performed on the surface of the resin material 85. As a result, as shown in FIG. 19, the excess resin material 82 remaining on the surface of the hard magnetic continuous film 81 is removed. Thus, the resin material 85 forms a predetermined pattern on the surface of the soft magnetic film 84.

  Thereafter, dry etching is performed on the surface of the soft magnetic film 84. As a result, as shown in FIG. 20, the soft magnetic film 84 is scraped off around the resin material 85. Thus, the soft magnetic body 68 is formed immediately below the resin material 85. The resin material 85 is removed. Thereafter, as shown in FIG. 21, a nonmagnetic material 87 is laminated on the surface of the nonmagnetic intermediate layer 73. A planarization process is performed on the nonmagnetic material 87. As a result, a recording magnetic layer 74 is formed on the nonmagnetic intermediate layer 73 as shown in FIG. The surface of the recording magnetic layer 74 is defined by a flat surface. The nonmagnetic material 87 forms a nonmagnetic material 65.

  A protective film 75 is formed on the surface of the recording magnetic layer 74. For the formation, for example, a CVD method (chemical vapor deposition method) is used. After the formation of the protective film 75, a lubricating film 76 is applied to the surface of the protective film 75. For application, for example, a dip method is used. In the dip method, the substrate 71 is immersed in a solution containing, for example, perfluoropolyether. Thus, the magnetic disk 14 is manufactured.

  FIG. 23 schematically shows the structure of a magnetic disk 14a according to the second embodiment of the present invention. In this magnetic disk 14a, the soft magnetic material 68 extends over the entire surface of the hard magnetic material 67, for example. Referring also to FIG. 24, the bit width Bw and the bit length BL of the soft magnetic body 68 coincide with the bit width Bw and the bit length BL of the hard magnetic body 67, respectively. The soft magnetic material 68 in the sub-track 62 decreases the film thickness as it moves away from the center line 63 of the recording track 61 toward the boundary line 66 in the cross track direction. As shown in FIG. 25, the magnetic dots 64 are embedded in the nonmagnetic material 65. A flat surface is defined by the surface of the nonmagnetic material 65. Like reference numerals are attached to the structure or components equivalent to those of the aforementioned magnetic disk 14.

  In the magnetic disk 14a, magnetic exchange coupling is realized between the hard magnetic body 67 and the soft magnetic body 68, as described above. As a result, when a recording magnetic field acts on the soft magnetic body 68 from the trailing end of the main magnetic pole 46 in writing binary information, the direction of magnetization of the soft magnetic body 68 is easily changed to a predetermined direction according to the direction of the recording magnetic field. Directed. As a result, the magnetization direction of the hard magnetic body 67 immediately below the soft magnetic body 68 is easily directed to a predetermined direction. In the hard magnetic body 67, magnetization is established in a predetermined direction throughout the entire area. Thus, magnetization in one direction is established by the magnetic dots 64. As a result, binary information is written to the magnetic dots 64.

  According to such a magnetic disk 14a, the soft magnetic body 68 has a relatively large film thickness inside the cross track direction. If a predetermined recording magnetic field acts on the soft magnetic body 68 on the center line 63 side, the magnetization is easily directed in a predetermined direction by the hard magnetic body 67. Moreover, since the thickness of the soft magnetic material 68 is relatively small outside in the cross track direction, the direction of magnetization is hardly changed by the hard magnetic material 67 even when a recording magnetic field acts. Even if a recording magnetic field acts on the adjacent recording tracks 61 across the boundary line 66, the occurrence of side erasure is suppressed. In the HDD 11, the recording density is improved. In addition, since the hard magnetic material 67 has a volume as before, the magnetic dots 64 can sufficiently withstand thermal fluctuations.

  Next, a method for manufacturing the magnetic disk 14a will be described. First, the backing layer 72 and the nonmagnetic intermediate layer 73 are formed on the surface of the substrate 71 with a predetermined film thickness based on, for example, sputtering. Thereafter, the hard magnetic body 67 is formed on the surface of the nonmagnetic intermediate layer 73 by the same manufacturing method as described above. A soft magnetic film 84 having a predetermined thickness is formed on the surface of the nonmagnetic intermediate layer 73 based on sputtering. The soft magnetic film 84 covers the hard magnetic body 67 on the surface of the nonmagnetic intermediate layer 73. Thereafter, as shown in FIG. 26, for example, an ultraviolet curable resin material 91 is applied to the surface of the soft magnetic film 84.

  As shown in FIG. 27, the surface of the mold 92 is superimposed on the resin material 91. The mold 92 is formed from an ultraviolet light transmissive material. A predetermined uneven pattern is formed on the surface of the mold 92. Here, recesses 92 a corresponding to the positions of the hard magnetic body 67 and the soft magnetic body 68 are formed on the surface of the mold 92. The bottom surface of the recess 92a is defined along a virtual plane that intersects the surface of the nonmagnetic intermediate layer 73 at a predetermined inclination angle. At this time, the surface of the substrate 71 is irradiated with ultraviolet rays. The resin material 91 is cured. The mold 92 is peeled off from the surface of the resin material 91.

  As a result, a predetermined pattern is transferred to the resin material 91 as shown in FIG. Here, the resin material 91 on the hard magnetic body 67 decreases in thickness as it goes from the inner end to the outer end of the hard magnetic body 67. Thereafter, as described above, reactive ion etching (RIE) is performed on the surface of the resin material 91. As shown in FIG. 29, the excess resin material 91 remaining on the surface of the soft magnetic film 84 is removed. Thus, the resin material 91 forms a predetermined pattern on the surface of the soft magnetic film 84.

  Thereafter, a dry etching process is performed on the surface of the soft magnetic film 84. As a result, the resin material 91 and the soft magnetic film 84 are scraped off on the hard magnetic body 67 as shown in FIG. The change in the thickness of the resin material 91 is reflected in the change in the thickness of the soft magnetic film 84. At the same time, the soft magnetic film 84 is scraped off around the resin material 91. Thus, the soft magnetic body 68 is formed. The soft magnetic body 68 decreases the film thickness toward the outside in the cross track direction.

  Thereafter, as shown in FIG. 31, a nonmagnetic material 87 is laminated on the surface of the nonmagnetic intermediate layer 73. A planarization process is performed on the nonmagnetic material 87. As a result, a recording magnetic layer 74 is formed on the nonmagnetic intermediate layer 73 as shown in FIG. The nonmagnetic material 87 forms a nonmagnetic material 65. The surface of the recording magnetic layer 74 is defined by a flat surface. Thereafter, a protective film 75 and a lubricating film 76 are formed on the surface of the recording magnetic layer 74 as described above. Thus, the magnetic disk 14a is manufactured.

  FIG. 33 schematically shows the structure of a magnetic disk 14b according to a third embodiment of the present invention. In the magnetic disk 14 b, the soft magnetic body 68 is disposed in a notch 95 formed on the surface of the hard magnetic body 67. That is, the thickness of the hard magnetic body 67 only needs to be increased outside the outer end of the soft magnetic body 68 as compared with the hard magnetic body 67 of the magnetic disk 14 described above. The hard magnetic body 67 is exposed on the surface of the recording magnetic layer 74. Like reference numerals are attached to the structure or components equivalent to those of the aforementioned magnetic disk 14. According to such a magnetic disk 14b, the same operation effect as the above-mentioned magnetic disk 14 is realized.

In manufacturing the magnetic disk 14b, as shown in FIG. 34, a hard magnetic body 96 is formed on the surface of the nonmagnetic intermediate film 73 based on, for example, sputtering and etching. The hard magnetic body 96 is made of a hard magnetic material. The hard magnetic body 96 is partially ion-doped. For example, N ₂ (nitrogen) ions are used as the ions. The hard magnetic body 96 is partially softened. As a result, a soft magnetic body 68 disposed on the hard magnetic body 67 is formed. In addition, it may be manufactured in the same manner as the magnetic disk 14 described above.

  In the HDD 11 as described above, a skew angle θ is defined for the flying head slider 22, that is, the electromagnetic transducer 27, as shown in FIG. 35. The skew angle θ is defined by the intersection angle between the center line of the electromagnetic transducer 27 and the center line 63. Therefore, in the above-described magnetic disks 14 to 14b, the radial lines passing on the intermediate positions of the center points of the magnetic dots 64 adjacent to each other in the cross track direction on the one subtrack 62 in the recording track 61 intersect. The center point of the magnetic dots 64 of the other subtrack 62 adjacent to each other is arranged on the intersecting line intersecting at the angle θ. Thus, the magnetic dots 64 are displaced in the down track direction by a deviation amount corresponding to the skew angle θ between the sub-tracks 62 adjacent to each other. Since the skew angle θ changes in the cross track direction of the magnetic disks 14 to 14b, the cross angle θ may be set according to the change.

(Appendix 1) a substrate,
A plurality of sub-tracks extending along the down-track direction on the substrate to establish a single recording track;
A magnetic dot formed from a hard magnetic material and a soft magnetic material arranged on the hard magnetic material, arranged in the down-track direction in each of the sub-tracks,
In each of the recording tracks, the soft magnetic material of the magnetic dot is defined on the boundary line side in the subtrack extending along a boundary line with the recording track adjacent to the recording track. A recording medium characterized in that the outer end is defined on the center line side of the recording track from the outer end of the recording track.

  (Supplementary note 2) The storage medium according to supplementary note 1, wherein the magnetic dots are arranged at equal intervals in the down-track direction in each of the sub-tracks.

  (Supplementary note 3) The storage medium according to supplementary note 2, wherein the magnetic dots of each of the sub-tracks are alternately arranged in a down-track direction with respect to the magnetic dots of the adjacent sub-tracks. Medium.

  (Supplementary Note 4) A plurality of sub-tracks extending along the down-track direction on the substrate to establish one recording track, and arranged in the down-track direction within each of the sub-tracks. A storage medium having a magnetic dot formed from a soft magnetic material disposed on a magnetic material, and facing the storage medium on a medium facing surface, and moves relative to the storage medium along the recording track A recording head adjacent to the recording track in each recording track, the recording track comprising a head slider and a magnetic recording head embedded in a medium facing surface of the head slider and defining a main magnetic pole facing the recording track In the sub-track extending along the boundary line, the soft magnetic body of the magnetic dot is the hard magnet defined on the boundary line side. Body storage apparatus characterized by defining the outer edge at the centerline side of the recording track of the outer end of.

(Appendix 5) a substrate,
A plurality of sub-tracks extending along the down-track direction on the substrate to establish a single recording track;
A magnetic dot formed from a hard magnetic material and a soft magnetic material arranged on the hard magnetic material, arranged in the down-track direction in each of the sub-tracks,
In each of the recording tracks, the soft magnetic material of the magnetic dots extends from the center line of the recording track toward the boundary line in the sub-track that extends along the boundary line with the recording track adjacent to the recording track. A storage medium characterized in that the film thickness decreases as the distance increases.

  (Supplementary note 6) The storage medium according to supplementary note 5, wherein the magnetic dots are arranged at equal intervals in the down-track direction in each of the sub-tracks.

  (Supplementary note 7) The storage medium according to supplementary note 6, wherein the magnetic dots of each of the sub-tracks are alternately arranged in a down-track direction with respect to the magnetic dots of the adjacent sub-tracks. Medium.

  (Supplementary Note 8) A plurality of sub tracks extending along the down track direction on the substrate to establish one recording track, and arranged in the down track direction in each of the sub tracks. A storage medium having a magnetic dot formed from a soft magnetic material disposed on a magnetic material, and facing the storage medium on a medium facing surface, and moves relative to the storage medium along the recording track A recording head adjacent to the recording track in each recording track, the recording track comprising a head slider and a magnetic recording head embedded in a medium facing surface of the head slider and defining a main magnetic pole facing the recording track In the sub-track extending along the boundary line, the soft magnetic body of the magnetic dot extends from the center line of the recording track. Storage apparatus characterized by decreasing the thickness as the distance toward the boundary lines.

1 is a plan view schematically showing an internal structure of a specific example of a storage device of the present invention, that is, a hard disk drive (HDD). FIG. It is an expansion perspective view which shows roughly the flying head slider which concerns on one specific example. It is a front view of the electromagnetic conversion element which shows roughly the electromagnetic conversion element observed from a medium opposing surface. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 1 is a plan view schematically showing the structure of a magnetic disk according to a first embodiment of the present invention. 1 is a partially enlarged plan view schematically showing the structure of a magnetic disk according to a first embodiment of the present invention. 1 is a partially enlarged perspective view schematically showing the structure of a magnetic disk according to a first embodiment of the present invention. 1 is a partial enlarged cross-sectional view schematically showing the structure of a magnetic disk according to a first embodiment of the present invention. It is a partial enlarged plan view which shows the relationship between a magnetic disk and an electromagnetic transducer. It is a partial expanded sectional view which shows schematically the process of forming a backing layer, a nonmagnetic intermediate | middle layer, and a magnetic continuous film on a board | substrate. It is a partial expanded sectional view which shows roughly the process of forming a hard-magnetic body on a nonmagnetic intermediate | middle layer. It is a partial expanded sectional view which shows roughly the process of forming a hard-magnetic body on a nonmagnetic intermediate | middle layer. It is a partial expanded sectional view which shows roughly the process of forming a hard-magnetic body on a nonmagnetic intermediate | middle layer. It is a partial expanded sectional view which shows roughly the process of forming a hard-magnetic body on a nonmagnetic intermediate | middle layer. It is a partial expanded sectional view which shows roughly the process of forming a soft-magnetic body on a hard-magnetic body. It is a partial expanded sectional view which shows roughly the process of forming a soft-magnetic body on a hard-magnetic body. It is a partial expanded sectional view which shows roughly the process of forming a soft-magnetic body on a hard-magnetic body. It is a partial expanded sectional view which shows roughly the process of forming a soft-magnetic body on a hard-magnetic body. It is a partial expanded sectional view which shows roughly the process of forming a soft-magnetic body on a hard-magnetic body. It is a partial expanded sectional view which shows roughly the process of forming a soft-magnetic body on a hard-magnetic body. It is a partial expanded sectional view which shows roughly the process of filling a nonmagnetic material between magnetic dots. It is a partial expanded sectional view which shows roughly the process of performing the planarization process to a nonmagnetic material. FIG. 5 is a partially enlarged plan view schematically showing a structure of a magnetic disk according to a second embodiment of the present invention. It is a partial expansion perspective view which shows roughly the structure of the magnetic disc concerning 2nd Embodiment of this invention. It is a partial expanded sectional view which shows roughly the structure of the magnetic disc concerning 2nd Embodiment of this invention. It is a partial expanded sectional view which shows roughly the process of forming a soft-magnetic body on a hard-magnetic body. It is a partial expanded sectional view which shows roughly the process of forming a soft-magnetic body on a hard-magnetic body. It is a partial expanded sectional view which shows roughly the process of forming a soft-magnetic body on a hard-magnetic body. It is a partial expanded sectional view which shows roughly the process of forming a soft-magnetic body on a hard-magnetic body. It is a partial expanded sectional view which shows roughly the process of forming a soft-magnetic body on a hard-magnetic body. It is a partial expanded sectional view which shows roughly the process of filling a nonmagnetic material between magnetic dots. It is a partial expanded sectional view which shows roughly the process of performing the planarization process to a nonmagnetic material. It is a partial expansion perspective view which shows roughly the structure of the magnetic disc concerning 3rd Embodiment of this invention. It is a partial expanded sectional view which shows roughly the process of forming a soft-magnetic body on a hard-magnetic body. It is a partial expanded plan view which shows roughly the structure of the magnetic disc which concerns on the modification of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 Storage device (hard disk drive), 14 Storage medium (magnetic disk), 22 Head slider (flying head slider), 28 Medium facing surface (floating surface), 45 Magnetic recording head (writing element), 46 Main magnetic pole, 61 Recording Track, 62 Subtrack, 63 Center line, 64 Magnetic dots, 66 Borderline, 67 Hard magnetic material, 68 Soft magnetic material, 71 Substrate.

Claims (4)

A substrate,
A plurality of sub-tracks extending along the down-track direction on the substrate to establish a single recording track;
A magnetic dot formed from a hard magnetic material and a soft magnetic material arranged on the hard magnetic material, arranged in the down-track direction in each of the sub-tracks,
In each of the recording tracks, the soft magnetic material of the magnetic dots is more than the outer end of the hard magnetic material in the subtrack extending along a boundary line with the recording track adjacent to the recording track. A storage medium characterized in that an outer end is defined on the center line side.   The storage medium according to claim 1, wherein the magnetic dots are arranged at equal intervals in the down-track direction in each of the subtracks.   3. The storage medium according to claim 2, wherein the magnetic dots of each of the sub-tracks are alternately arranged in a down-track direction with respect to the magnetic dots of the adjacent sub-tracks.   A plurality of subtracks extending along the downtrack direction on the substrate to establish one recording track, and arranged in the downtrack direction within each of the subtracks, on the hard magnetic body and the hard magnetic body A storage medium having magnetic dots formed from a soft magnetic material disposed, a head slider facing the storage medium at a medium facing surface and moving relative to the storage medium along the recording track; A magnetic recording head embedded in a medium facing surface of the head slider and defining a main magnetic pole facing the recording track, and a boundary line between the recording track and the recording track adjacent to the recording track in each recording track In the sub-track extending along the magnetic track, the soft magnetic material of the magnetic dots is more in the recording track than the outer end of the hard magnetic material. Storage apparatus characterized by defining the outer end in a line side.

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