JP2010146687A - Magnetic recording medium, magnetic storage device, and manufacturing method of magnetic recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a stable servo pattern having high output with a simple structure. <P>SOLUTION: The servo pattern is divided into a first pattern group and a second pattern group, the first and second patterns are alternately disposed in a magnetic head advancing direction in a servo information area, a prescribed region wherein only the first patterns are provided in an area other than the servo information area and thus the servo pattern is so constituted as to have a part where all the first patterns are disposed in the prescribed region and a part disposed in the servo information area. The whole servo patterns are once magnetized in the same direction and then the prescribed region is selectively magnetized to reverse the magnetization directions of the first pattern group and second pattern group to each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a magnetic recording medium in which a servo pattern used for positioning of a magnetic head is formed on a perpendicular magnetic recording surface, a magnetic storage device, and a method for manufacturing the magnetic recording medium.

  Conventionally, magnetic storage devices such as hard disks have increased in capacity, and there has been a demand for improvement in recording density of magnetic recording media. In order to meet the demand for higher density, a perpendicular magnetic recording system in which magnetization is performed in a direction perpendicular to the recording surface is used.

  In recent years, research and development related to DTM (Discreet Track Media) and BPM (Bit Patterned Media) have been actively conducted in order to further improve recording density.

  The DTM can greatly improve ATI (Adjacent Track Interference) resistance that erases information on adjacent tracks by providing physical grooves and lines having different magnetic characteristics between recording tracks. In addition, BPM can dramatically improve the recording / reproducing characteristics in the down-track direction in addition to the ATI resistance by forming a three-dimensional magnetic bit having a structure also in the down-track direction. In addition, it is attracting attention as a next-generation information recording medium.

  When an information recording structure such as DTM or BPM is formed in advance, a servo pattern for position control of the magnetic head is also formed in advance.

  Here, in the perpendicular magnetic recording system, the static magnetic field from the adjacent magnetization region (adjacent bit) acts as a demagnetizing field and works in the direction of reversing the magnetization. In the area where user data is written, since the magnetization direction varies relatively, the possibility of magnetization reversal is relatively low, but in the servo pattern, the same magnetization direction is often continuous compared to user data, Since the possibility of inversion increases, the written information becomes unstable.

  In addition, in DTM and BPM, the information in the data part is detected by the difference between the output of the N pole and the S pole, but the whole is magnetized collectively with a servo pattern and the presence or absence of a predetermined magnetization direction is detected. As a result, the output is halved compared to the data portion in which both the N pole and the S pole exist, and the detection accuracy of the servo information is lowered.

  Therefore, conventionally, by newly providing a magnetic layer under the servo pattern, the direction of magnetization is changed with respect to the depth direction of the recording medium, thereby ensuring the signal output of the servo unit and the stability of the magnetization state. Has been proposed.

JP 2007-95115 A

  However, if a new magnetic layer is added, it is necessary to precisely adjust characteristics such as coercive force and saturation magnetization so as to change the direction of magnetization between the magnetic layers. In addition, it is very difficult in terms of the process for the user to change the laminated structure between the user data area in which information is actually recorded and the servo pattern. In addition, when the structure of the user data area is matched with the servo pattern, there is a problem that the characteristics of the area in which the user records information are limited.

  Therefore, it has been an important issue to form a stable servo pattern with a large output without changing the laminated structure.

  The present magnetic recording medium, magnetic storage device, and method of manufacturing the magnetic recording medium have been made to solve the above-described problems of the prior art and to solve the problems, and have a simple configuration, large output, and stability. An object of the present invention is to provide a magnetic recording medium, a magnetic storage device, and a method of manufacturing the magnetic recording medium on which a servo pattern is formed.

  In order to solve the above-described problems and achieve the object, the disclosed medium, apparatus, and method divide the servo pattern into a first pattern group and a second pattern group, and in the servo information area, the traveling direction of the magnetic head The first pattern and the second pattern are alternately arranged, a predetermined area in which only the first pattern is arranged in a place other than the servo information area is provided, and a portion in which all the first patterns are arranged in the predetermined area and the servo information area It is comprised so that it may have a part arrange | positioned. The servo pattern is once magnetized in the same direction and then selectively magnetized in a predetermined region, thereby reversing the magnetization directions of the first pattern group and the second pattern group.

  According to the disclosed medium, apparatus, and method, a magnetic recording medium, a magnetic storage apparatus, and a method for manufacturing the magnetic recording medium in which a large output and a stable servo pattern are formed by alternately changing the magnetization direction with a simple configuration There is an effect that can be obtained.

  Hereinafter, a magnetic recording medium, a magnetic storage device, and a method for manufacturing the magnetic recording medium according to the present embodiment will be described in detail with reference to the drawings.

  FIG. 1 is an explanatory diagram for explaining an outline of servo pattern formation according to the present embodiment. The servo pattern shown in FIG. 1 has a pattern P1 that is a first pattern and a pattern P2 that is a second pattern. The patterns P1 and P2 are arranged so as to alternately pass over the pattern P1 and the pattern P2 when the magnetic head moves in the down track direction. Only the pattern P1 exists, and a region where the pattern P2 does not exist is included as the selective magnetization region. This selective arrival area is provided in a place other than the servo information area that provides positioning information to the magnetic head, that is, in a guard band in the servo pattern.

  When the entire servo pattern having such an arrangement is magnetized in the same direction and only the selective magnetization region is magnetized in the reverse direction, only the portion belonging to the selective magnetization region in the pattern P1 is magnetized in the reverse direction.

  Thereafter, when magnetic fields with different directions are alternately applied to the entire servo pattern, the entire pattern P1 is magnetized in the opposite direction while maintaining the magnetization state of the pattern P2.

  As a result, the patterns P1 and P2 having different magnetization directions with respect to the down track direction can be alternately arranged.

  FIG. 2 is a schematic configuration diagram illustrating a schematic configuration of a hard disk device using a servo pattern according to the present embodiment. As shown in FIG. 2, the hard disk device 1 reads and writes magnetic information to and from the base 10, a recording medium 11 that records magnetic information, a spindle motor 17 that rotates the recording medium 11, and the magnetic recording medium 11. The magnetic head 12 includes a suspension 14 that holds the magnetic head 12, a voice coil motor 16 that controls the position of the magnetic head 12 by swinging the suspension 14, and a control circuit 15 that controls the entire magnetic storage device 1.

  As shown in FIG. 3, an information recording area track 11b for storing user data is formed substantially concentrically on the recording surface of the magnetic recording medium 11, and the head position is sector-shaped with respect to the information recording area track 11b. A servo pattern 11a for control is formed. The position of the magnetic head 12 is controlled based on the information of the servo pattern 11a, so that information can be recorded / reproduced at a desired position on the magnetic recording medium 11.

  The magnetic recording medium 11 is DTM or BPM. FIG. 4 is an explanatory diagram for explaining the shape of the information recording area track 11b in the DTM. In the configuration shown in FIG. 4, the tracks are magnetically separated by physically providing grooves between the tracks. FIG. 5 is an explanatory diagram for explaining the shape of the information recording area track 11b in the BPM. In the configuration shown in FIG. 5, grooves are provided in the down track direction in addition to between the tracks to magnetically separate the bits.

  FIG. 6 is a schematic diagram schematically showing a part of a conventional servo pattern. In general, a servo pattern has a pattern continuous in a direction perpendicular to the down-track direction of a track on which information is recorded. In the case of BPM or DTM, the servo pattern portion is generally magnetized in a certain direction.

  At that time, as shown in FIG. 4, the magnetization reversal part partially occurred in the conventional configuration. The occurrence of this magnetization reversal will be described with reference to FIG. In FIG. 7, the servo magnetic layer 31 is formed on the substrate 30, and the whole is magnetized in the same direction. At this time, if each is magnetized in the perpendicular direction by the perpendicular magnetic recording method, the static magnetic field from the next acts as a demagnetizing field and works in the direction of reversing the magnetization. When magnetization reversal occurs in the servo pattern in this way, incorrect position information is given to control the position of the magnetic head.

  Therefore, as shown in FIG. 8, it is desirable that the servo pattern be alternately reversed in magnetization direction with respect to the cross track direction. In this configuration, since the magnetization directions of the adjacent ones are different from each other, the magnetization directions are strengthened, so that the magnetization reversal can be prevented.

  Further, in DTM and BPM, information in the information recording area track 11b, that is, the data portion storing user data is detected by the difference between the output of the N pole and the S pole. In the servo pattern configuration shown in FIG. The output is halved, and the servo pattern detection accuracy decreases.

  As shown in FIG. 9, if a magnetic layer 32 is provided between the servo magnetic layer 31 and the substrate 30 and the direction of magnetization changes with respect to the depth direction of the recording medium, the servo pattern signal Although it is possible to ensure the output and the stability of the magnetization state, precise adjustment of characteristics such as coercive force and saturation magnetization is required between the servo magnetic layer 31 and the magnetic layer 32.

  In contrast to such a conventional technique, the servo pattern according to the present embodiment obtains a pattern in which the magnetization direction is alternately reversed as shown in FIG. 8 without changing the laminated structure by the servo pattern shape and the magnetization process. be able to.

  Next, with reference to FIGS. 10 to 13, the shape of the servo pattern and the magnetization process according to the present embodiment will be described in more detail. FIG. 10 shows an example of a specific shape of the servo pattern. The servo pattern has an address part and a phase part by a preamble and a gray code.

  The brimble is an area indicating the start of the servo pattern, the address portion indicates the address itself, and the phase portion indicates a positional deviation within the range of the same address. In the following description, in order to simplify the description, description will be made mainly using the preamble portion as an example.

  In the pattern shown in FIG. 10, the pattern of the preamble portion extends in the cross track direction perpendicular to the down track direction in which the magnetic head moves. Further, the connecting portion extends in the down track direction.

  The patterns extending in the cross-track direction are connected to the connecting portions every other in the down-track direction, and are formed by combining comb-shaped patterns. In other words, the pattern of the preamble portion extends from each connecting portion on both sides in the down track direction. Each connecting portion corresponds to the patterns P1 and P2 every other portion, and the pattern of the preamble portion extending from the connecting portion also belongs to any of the patterns P1 and P2.

  Any pattern belonging to the brimble portion does not belong to both the patterns P1 and P2, and the connecting portion is a predetermined area that does not include the other pattern for each pattern.

  Further, in the state of FIG. 10, the entire servo pattern, that is, both patterns P1 and P2 are magnetized in the same direction. Here, FIG. 10 is a top view as seen from the air bearing surface of the magnetic head, and it is assumed that the magnetic head is magnetized by a uniform magnetic field of N pole → S pole perpendicular to the substrate side.

  Next, as shown in FIG. 11, when the magnet is magnetized in the direction opposite to the connecting portion of the pattern P1, that is, in the direction from the N pole to the S pole perpendicular from the magnetic head side to the substrate side, only the connecting portion becomes the S pole. .

  Further, when a uniform magnetic field of N pole → S pole perpendicular to the substrate side from the magnetic head side to the substrate side is applied from the outside, the region magnetized to the S pole is expanded as shown in FIG. Next, when the application of the magnetic field of the S pole → N pole and the application of the inverted magnetic field N pole → S pole are repeated, a preamble portion with reversed magnetization is formed as shown in FIG. It should be noted that in the address portion and the phase portion, inversion patterns are alternately formed in the same manner in principle.

  This magnetization process will be described with reference to a flowchart. FIG. 14 is a flowchart for explaining a magnetization process using a magnetic transfer mold. As shown in FIG. 15, the magnetic transfer mold has a magnetizing pattern 42 formed concentrically.

  Returning to FIG. 14, first, the entire magnetic recording medium is magnetized in the N-pole-> S-pole direction from above the recording surface using an electromagnet or a permanent magnet (S101). Next, the magnetic transfer mold 40 shown in FIG. 15 is arranged close to the magnetic recording medium (S102). Although not shown in FIG. 15, the magnetic recording medium and the magnetic transfer mold 40 are preliminarily formed with cross marks for positioning in the inner peripheral area and the outer peripheral area, and these positions are aligned. Place the mold. Thereby, it is possible to align the positions in the XY directions with an accuracy of ± 10 μm or less.

  Next, with the magnetic transfer mold 40 disposed, a magnetic field is applied from the upper side of the recording surface to the south pole to the north pole (S103). The application of this magnetic field can selectively magnetize the connecting portion.

  Thereafter, the magnetic transfer mold 40 is retracted (S104), and a magnetic field in the S-pole → N-pole direction is applied from above the recording surface (S105), and a magnetic field in the N-pole → S-pole direction is applied from above the recording surface (S106). . The number of executions N of steps S105 and S106 is compared with the prescribed number N0 (S107). If the prescribed number has not been reached (S107, Yes), 1 is added to the number N of executions (S108), and the process returns to step S105. Then, when the number of executions N reaches the specified number (S107, No), the process is terminated.

  In FIG. 14, the selective magnetization using the magnetic transfer mold is exemplified. However, for example, the connecting portion can be selectively magnetized by the magnetic head using the magnetizing apparatus shown in FIG. The magnetizing apparatus 50 shown in FIG. 16 includes a main controller unit 51, a memory 52, a data buffer memory 53, a preamplifier 54, and a servo controller 55 therein.

  The data buffer memory 53 stores the BPM arrival position, that is, the position data of the connecting portion. The main controller unit 51 reads the position data of the connecting portion and controls the preamplifier 54 and the servo controller 55 while using the memory 52 as a main storage device to magnetize the BPM.

  The servo controller 55 operates the spindle motor 61 to rotate the BPM and operates the voice coil motor 62 to control the position of the magnetic head 64 attached to the suspension 63. Then, the preamplifier 54 controls the magnetic field of the magnetic head 64 to execute magnetization on the BPM.

  FIG. 17 is a flowchart for explaining a magnetization process using the magnetizing device 50. In this magnetization process, first, the entire magnetic recording medium is magnetized in the N-pole → S-pole direction from above the recording surface using an electromagnet or a permanent magnet (S201). Next, the magnetic head 64 shown in FIG. 16 is loaded (S202).

  Next, while controlling the position of the magnetic head 64, a magnetic field is applied from the upper side of the recording surface to the south pole to the north pole (S203). The application of this magnetic field can selectively magnetize the connecting portion.

  Thereafter, the magnetic head 64 is retracted (S204), and a magnetic field in the S-pole → N-pole direction is applied from above the recording surface (S205), and a magnetic field in the N-pole → S-pole direction is applied from above the recording surface (S206). The number of executions N of steps S205 and S206 is compared with the prescribed number N0 (S207). If the prescribed number has not been reached (S207, Yes), 1 is added to the number N of executions (S208), and the process returns to step S205. Then, when the number of executions N reaches the specified number (S207, No), the process is terminated.

  Next, production of BPM will be described. FIG. 18 is an explanatory diagram for explaining a BPM manufacturing process. In BPM production, first, a resist with a thickness of several tens of nanometers is applied on a precisely polished glass master (S301), and a bit pattern is formed by etching (S303) after electron beam exposure (S302). Thereafter, the resist is removed by ashing or the like (S304), and the master is completed by washing (S305).

  In the electron beam exposure, for example, an exposure apparatus having the configuration shown in FIG. 19 is used. In the exposure apparatus shown in FIG. 19, the main controller 71 controls the spindle motor driver 75 and the stage driver 76 to control the position of the BPM master, and also controls the electron source controller 73 and the electron beam controller 74, so that the BPM To control the electron beam irradiated on the surface.

  More specifically, a BPM master disc coated with a resist and pre-baked is attached to an air spindle motor 78 and rotated at a desired rotational speed. On the other hand, after the electron beam from the electron source passes through an electron beam adjustment system using an electromagnetic field, the electron beam is focused on the BPM master by an electron beam focusing system which is also composed of an electromagnet. The main controller 71 adjusts the rotation position of the master disk by the spindle motor driver 75 based on information from the formatter 72 and adjusts the position with respect to the electron beam focusing position by using the stage driver 76. Further, based on information from the formatter 72, the intensity and position of the electron beam are modulated at high speed, and bit information is recorded.

  Returning to FIG. 18, the explanation will be continued. Adhesion layer deposition (S312), SUL (Soft Under Layer) layer deposition (S313), underlayer and intermediate layer deposition on the glass substrate (S311) used for the BPM medium. (S314), perpendicular magnetic layer deposition (S315), and protective layer deposition (S316) are sequentially executed. For each film formation, for example, a sputtering method or the like can be used.

  The substrate is filled with a nanoimprint resist using the BPM master described above (S317), irradiated with UV (S318), and the master is peeled off (S319) to form a bit on the substrate. To do.

  Further, the formed resist bit is etched (S320), and the resist is removed by ashing (S321), thereby forming a magnetic bit pattern. Further, after forming a filling layer of metal or the like (S322), the BPM medium is planarized by reverse sputtering or the like (S323). Then, after cleaning (S324), a protective film is formed (325) and a lubricant is applied (S326), whereby the BPM structure shown in FIG. 20 can be formed.

In this embodiment, an artificial lattice film in which Co and Pd are alternately laminated with a sub-nanometer thickness is used as the perpendicular magnetic layer. In particular, the preamble portion is configured as shown in FIG. An example of detailed parameters is
Coercive force Hc: 0.3 T (= 3 kOe)
Saturation magnetic flux density Bs: 0.08T (800 emu / cc)
Magnetic layer thickness: 15 nm
Preamble pitch: 60nm
Preamble width: 40nm
Lp: 2.4μm
Lk: 300μm
Track pitch: 100nm
Number of track sectors: 220
It is.

  FIG. 22 plots the magnetization reversal error rate of the preamble portion with respect to the magnetization application cycle while changing the magnetic field strength applied alternately after the selective magnetization in three ways. By setting H = Hc-Bs = 0.22T, magnetization reversal with almost no error can be achieved with 10 cycles of application. In a magnetic field of more than that, the inversion position moves greatly every time the magnetization is applied, so the error does not decrease. Also, in a magnetic field less than H = Hc-Bs, the error rate does not decrease unless the number of cycles is further increased. By setting H = Hc-Bs, a desired magnetization state can be realized quickly and stably.

  As described above, the servo pattern according to the present embodiment has a magnetic pattern in which line-shaped portions that are magnetically continuously formed are formed substantially in parallel, and the plurality of magnetic patterns Of these, every other pattern adjacent to the line shape in a direction substantially perpendicular to the line shape is connected. Thereby, the magnetic pattern in which the line shapes are connected has a comb-teeth shape with the line shapes as teeth and the connecting portions as the back, and the connecting portions are parallel to the tracks on which information is recorded.

  And after magnetizing the whole in one direction as the first step, the magnetic pattern is magnetized in the opposite direction as the second step, and alternately directed from the outside as the third step. By applying the magnetic field a plurality of times, the line shape portion has a configuration in which the magnetization direction is reversed between adjacent line shapes.

  As described above, the servo pattern is divided into the first pattern group and the second pattern group, and in the servo information area, the first pattern and the second pattern are alternately arranged in the traveling direction of the magnetic head. If a predetermined area in which only the first pattern is arranged is provided at a place, and all the first patterns have a portion arranged in the predetermined area and a portion arranged in the servo information area, the whole is once the same. After magnetization in the direction, the magnetization direction of the first pattern group and the second pattern group can be reversed by selectively magnetizing the predetermined region.

  Therefore, a stable servo pattern can be formed with a simple configuration and a large output. As a result, an information recording medium having high reliability and capable of high density recording can be provided at low cost.

  In addition, a present Example is an example to the last, and this invention can deform | transform and implement the structure and procedure suitably. For example, in the present embodiment, the case where both the first pattern and the second pattern have a connecting portion and only the first pattern connecting portion is selectively magnetized has been described as an example. It is possible to implement with appropriate changes.

  For example, as shown in FIG. 23, the shape of both the first pattern P1 and the second pattern P2 is a shape in which the lengths of the short line portions are arranged with a gap in the cross track direction, and the first pattern P1 and the second pattern P2 The pattern P2 and the pattern P2 may be arranged alternately in the down-track direction and with the gap position shifted. In this case, the gap portion of the second pattern P2 becomes a predetermined region where only the first pattern P1 exists, and this predetermined region can be used for selective magnetization.

  Further, as shown in FIG. 24, the second pattern P2 has a shape in which the lengths of the short line portions are arranged with a gap in the cross track direction, and the first pattern P1 extends continuously in the cross track direction. It is also good. If the first pattern P1 and the second pattern P2 are alternately arranged in the down-track direction, the gap portion of the second pattern P2 becomes a predetermined area where only the first pattern P1 exists, and this predetermined area is selectively used. Can be used for proper magnetization.

  Further, as shown in FIG. 25, the second pattern P2 has a shape in which the lengths of the short line portions are arranged with a gap in the cross track direction, and the first pattern P1 continuously extends in the cross track direction. And it is good also as a shape connected in the down-track direction. In this configuration, the gap portion of the second pattern P2 becomes a predetermined region where only the connecting portion of the first pattern P1 exists, and this predetermined region can be used for selective magnetization.

FIG. 1 is an explanatory diagram for explaining an outline of servo pattern formation according to the present embodiment. FIG. 2 is a schematic configuration diagram illustrating a schematic configuration of a hard disk device using a servo pattern according to the present embodiment. FIG. 3 is an explanatory diagram for explaining the recording surface of the magnetic recording medium. FIG. 4 is an explanatory diagram for explaining the shape of the information recording area track in the DTM. FIG. 5 is an explanatory diagram for explaining the shape of an information recording area track in BPM. FIG. 6 is a schematic diagram schematically showing a part of a conventional servo pattern. FIG. 7 is an explanatory diagram for explaining the occurrence of magnetization reversal. FIG. 8 is an explanatory diagram for explaining a servo pattern whose magnetization directions are alternately reversed. FIG. 9 is an explanatory diagram illustrating a configuration in which the magnetization direction changes with respect to the depth direction of the recording medium. FIG. 10 is an explanatory diagram for explaining a specific shape of the servo pattern. FIG. 11 is an explanatory diagram for explaining a servo pattern in which the coupling portion is selectively magnetized. FIG. 12 is an explanatory diagram for explaining expansion of the magnetization direction of the connecting portion. FIG. 13 is an explanatory diagram for explaining a preamble portion in which magnetization is alternately reversed. FIG. 14 is a flowchart for explaining a magnetization process using a magnetic transfer mold. FIG. 15 is an explanatory diagram for explaining the configuration of the magnetic transfer mold. FIG. 16 is an explanatory diagram illustrating the configuration of the magnetizing device. FIG. 17 is a flowchart for explaining a magnetization process using the magnetizing device 50. FIG. 18 is an explanatory diagram for explaining a BPM manufacturing process. FIG. 19 is an explanatory diagram illustrating the configuration of the exposure apparatus. FIG. 20 is an explanatory diagram for explaining the cross-sectional structure of the BPM. FIG. 21 is an explanatory diagram illustrating the configuration of the preamble portion. FIG. 22 is an explanatory diagram for explaining the relationship between the magnetic field strength and the magnetization reversal error rate of the preamble portion. FIG. 23 shows a modification of the servo pattern shape. (Part 1) FIG. 24 shows a modification of the servo pattern shape. (Part 2) FIG. 25 shows a modification of the servo pattern shape. (Part 3)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic disk apparatus 10 Base 11 Recording medium 11a Servo pattern 11b Information recording area track 12 Magnetic head 14 Suspension 15 Control circuit 16 Voice coil motor 17 Spindle motor 30 Substrate 31 Servo part magnetic layer 32 Magnetic layer 50 Magnetizing apparatus 51 Main controller unit 52 memory 53 data buffer memory 54 preamplifier 55 servo controller 61 spindle motor 62 voice coil motor 63 suspension 64 magnetic head 71 main controller 72 formatter 73 electron source controller 74 electron beam controller 75 spindle motor driver 76 stage driver 77 stage 78 spindle motor P1 first 1 pattern P2 2nd pattern

Claims (7)

A magnetic recording medium having a servo pattern used for positioning a magnetic head formed on a perpendicular magnetic recording surface,
The servo pattern has a first pattern group and a second pattern group magnetized in different directions,
In the servo information area that provides positioning information to the magnetic head among the servo patterns, the first pattern and the second pattern are alternately arranged with respect to the traveling direction of the magnetic head,
Among the servo patterns, having one or a plurality of predetermined areas in which only the first pattern is arranged at a place other than the servo information area,
A magnetic recording medium, wherein all the first patterns have a portion arranged in the predetermined area and a portion arranged in the servo information area.   The magnetic recording medium according to claim 1, further comprising a connecting portion that magnetically connects the plurality of first patterns in the predetermined area.   The first pattern and the second pattern are magnetized in the same direction, magnetized in the opposite direction by selective magnetization with respect to the predetermined region, and then applied with different magnetic fields. The magnetic recording medium according to claim 1, wherein the magnetic recording medium is a magnetic recording medium.   The magnetic recording medium according to claim 1, wherein the selective magnetization is performed using a magnetic transfer mold.   The magnetic field applied when the magnetic fields having different directions are applied alternately are substantially the same as the difference between the coercive force and the saturation magnetic flux density of the servo pattern. 4. The magnetic recording medium according to 4. A magnetic head for reading and writing magnetic information; and a magnetic recording medium having a servo pattern used for positioning of the magnetic head formed on a perpendicular magnetic recording surface,
The servo pattern has a first pattern group and a second pattern group magnetized in different directions,
In the servo information area that provides positioning information to the magnetic head among the servo patterns, the first pattern and the second pattern are alternately arranged with respect to the traveling direction of the magnetic head,
Among the servo patterns, having one or a plurality of predetermined areas in which only the first pattern is arranged at a place other than the servo information area,
All the first patterns have a portion arranged in the predetermined area and a portion arranged in the servo information area. A method of manufacturing a magnetic recording medium in which a servo pattern used for positioning a magnetic head is formed on a perpendicular magnetic recording surface,
For the first pattern and the second pattern arranged alternately with respect to the traveling direction of the magnetic head, a co-directional magnetization step for magnetizing both the first pattern group and the second pattern group in the same direction;
A selective magnetization step that selectively magnetizes a predetermined region that includes the first pattern and does not include the second pattern and in a direction opposite to the magnetization direction of the same-direction magnetization step;
A different-direction magnetization step of alternately applying different magnetic fields to both the first pattern group and the second pattern group;
A method for producing a magnetic recording medium, comprising:

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