JP2009217889A - Magnetic transfer master body, method of manufacturing magnetic transfer body, magnetic recording medium, and magnetic recording system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic transfer master body which maintains vertical symmetry of magnetic transfer waveform without changing L/S ratio of a magnetic pattern when microfabricating the magnetic transfer body, to provide a magnetic transfer unit thereof, magnetic recording medium manufactured by using the magnetic transfer unit, and magnetic recording system using the magnetic recording medium. <P>SOLUTION: A pattern concave part having a magnetic body corresponding to the magnetic pattern is disposed on the surface of the substrate of the magnetic transfer body, magnetic material consisting of a first magnetic substance is placed in the pattern concave part, magnetic material consisting of a second magnetic substance is placed at least in a part of the boundary between the substrate on the surface and the first magnetic substance placed in the pattern concave part, a relation M<SB>S1</SB>>M<SB>S2</SB>is provided between the saturation magnetization M<SB>S1</SB>of the first magnetic substance and the saturation magnetization M<SB>S2</SB>of the second magnetic substance, and material of the second magnetic substance is different from that of the substrate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a magnetic transfer master body that magnetically transfers a magnetic pattern such as a servo signal to a magnetic disk medium used in a magnetic recording apparatus, a method for manufacturing the magnetic transfer master body, and a magnetic recording in which a magnetic pattern is formed by the magnetic transfer master body. The present invention relates to a medium and a magnetic recording apparatus using the magnetic recording medium.

  In order to position the head on the magnetic disk medium, data areas and servo areas are alternately formed on each track. Conventionally, servo data has been recorded by a servo track writing (STW) method using a dedicated head. The servo area on the magnetic disk is divided into a preamble area, a servo mark area, and a servo data area in order from the side where the head enters (upstream side). In the preamble region, positive and negative magnetic poles are alternately formed at uniform intervals along the circumferential direction. In the servo data area, magnetic poles are formed in a predetermined pattern that changes in the radial direction.

  In the HDD, a synchronization signal is obtained from magnetic information read in the preamble area. The head is accurately positioned on the recording track based on the magnetic information read from the servo data area.

  However, as the recording density of the data area increases with the recent increase in the density of hard disk drives, higher density is also required for the servo information necessary for head positioning. In the conventional STW method, an increase in time required for recording servo information per unit due to an increase in servo information as data density increases is one of the problems in mass production of hard disk devices.

  On the other hand, a servo write method using a magnetic transfer method has recently been proposed.

  In the magnetic transfer method, a magnetic transfer master body on which servo information is recorded in advance is brought into close contact with a magnetic recording medium, and servo information is recorded by applying a magnetic field from the outside. As for this magnetic transfer method, an application example of a conventional longitudinal magnetic recording system using a longitudinal magnetic recording medium has been reported (Patent Document 1).

  FIG. 7 shows an example of a cross-sectional view of a conventional magnetic transfer master body. An example of a conventional magnetic transfer master body will be described with reference to FIG. In the figure, in the three examples I), II), and III), the master substrate 71, 73, and 75 all have a cross-section of the uneven region corresponding to the servo pattern.

  I), in order to transfer the magnetization pattern corresponding to the servo pattern to the magnetic recording medium, for example, the surface of the master substrate 71 made of silicon, Ni or the like is made uneven by a thin film forming technique, and the surface has a high magnetic permeability. A layer of a soft magnetic material 72 is formed.

  II) shows a chevron-shaped type in which both ends of the convex portion are tapered. For example, a mountain-shaped convex portion is formed on the surface of the master body substrate 73 made of silicon, Ni or the like by a thin film forming technique, and a layer of a soft magnetic material 74 of a high magnetic permeability material is formed on the surface from above in the figure by sputtering. Is. It is easier to create a master body by this method than the method I).

  In III), a concave groove is formed in a master substrate 75 made of silicon, and the groove is filled with a soft magnetic material 76 of a high magnetic permeability material.

  On the other hand, with respect to magnetic recording media, perpendicular magnetic recording methods have progressed compared to conventional in-plane magnetic recording methods, and magnetic transfer methods have also been perpendicular to the magnetic recording medium surface compared to methods in which a magnetic field is applied horizontally to a magnetic recording medium. A method of applying a magnetic field in the direction has been required.

  In a transfer method in which a magnetic field is applied perpendicularly to a magnetic recording medium, an initialization magnetic field is applied in a direction perpendicular to the magnetic recording medium surface, and then the magnetic transfer master body is brought into close contact with the magnetic recording medium so that a magnetic field is applied in a direction opposite to the initialization magnetic field. In this method, a servo pattern or the like is transferred to a magnetic recording medium by applying.

  As the magnetic recording system shifts from the in-plane magnetic recording system to the perpendicular magnetic recording system, the conditions required for the magnetic transfer master body at the time of magnetic transfer are becoming stricter.

  As an example, in a magnetic recording medium of in-plane magnetic recording system, a magnetic transfer master body having a track record in which the head can be on-tracked by a servo signal recorded by magnetic transfer is applied to a magnetic recording medium of perpendicular magnetic recording system. In this case, a problem peculiar to the perpendicularly applied magnetic transfer has occurred, such that the magnetically transferred waveform is vertically asymmetric and cannot be on-tracked.

  FIG. 3 shows an example of a transfer magnetic field waveform simulation result in a magnetic recording medium after perpendicularly applied magnetic transfer using a conventional magnetic transfer master body. FIG. 3 shows an example of magnetic transfer to a magnetic recording medium using a magnetic transfer master body of type II) in FIG. The simulation results using the finite element method are shown.

  In FIG. 3, assuming that the magnetic field strength in the lower direction of the drawing is the magnetic field strength in the initialization direction of the magnetic recording medium, the magnetic field strength distribution of the portion to be magnetized in the opposite direction by perpendicularly applied magnetic transfer forms two peaks. An example is shown. This is because the two peaks correspond to the edge portions of the convex portions that come into contact with the magnetic recording medium of the magnetic transfer master body corresponding to the servo pattern, and the magnetic flux tends to concentrate.

  In the magnetic recording medium that has been magnetically transferred, it is desirable that the magnetic field strength distribution in the magnetic recording medium after the magnetic transfer has a shape in which the magnetic field strength distribution in the lower direction and the magnetic field strength distribution in the upper direction are substantially equal. Therefore, as a method for coping with this, by narrowing the width of the convex portion and narrowing the distance between the edges, the two peaks in FIG. 3 tend to approach and become one peak. When the distance between adjacent soft magnetic materials appearing on the surface of the magnetic transfer master body is S and the width of the soft magnetic material appearing on the surface is L, (L ÷ S) ≦ 0.35 The inventor disclosed in Japanese Patent Application No. 2007-30728 (Patent Document 2) a method in which the transfer magnetic field waveform applied to the magnetic recording medium during the applied magnetic transfer is nearly symmetrical.

  In the method disclosed in Patent Document 2 above, in the case of perpendicularly applied magnetic transfer, the vertical symmetry of the transfer magnetic field waveform due to the magnetic flux constriction effect on the end surface of the soft magnetic material appearing on the surface of the master substrate. In addition, a sufficient magnetic flux is supplied by the divergent shape at the other end of the soft magnetic material so that stable magnetic transfer can be performed. That is, the L / S ratio at the time of fine surface processing is changed, the distance between the edges of the servo pattern is shortened, and the magnetic flux concentrated on the edges is relaxed.

  However, in a magnetic recording medium, a portion caused by a servo pattern dimension being different between the inner circumference and the outer circumference of the magnetic recording medium, and having a waveform shift with respect to a pattern having a different dimension width in the servo pattern. The problem of misalignment of the typical transcription waveform remained.

  FIG. 8 shows an example of a transfer magnetic field waveform calculated by simulating a case where the pitch is changed with the concave / convex ratio of the master pattern = 3.1. In the example of II) in FIG. 7, when the concave / convex pitch is changed with the concave / convex ratio of the master pattern = 3.1 (L / S = 3.1), as an example, a soft magnetic body positioned on the surface of the magnetic transfer master body 4 is an example of transfer magnetic field waveforms obtained by comparing and comparing a magnetic field intensity distribution waveform in a magnetic recording medium after perpendicularly applied magnetic transfer using a magnetic transfer master body having a pitch of 100 nm and 200 nm by simulation using a finite element method. .

  In FIG. 8, when L / S = 3.1, the waveform of the transfer magnetic field strength of the magnetic recording medium magnetically transferred when the pitch of the soft magnetic material is 100 nm has one peak, but the upper and lower waveforms are symmetrical. When L / S = 3.1, and the pitch of the soft magnetic material is 200 nm, it has two peaks.

As described above, it was found that even if the value of L / S is kept constant, partial transfer waveform deviation occurs depending on conditions.
JP 2003-141715 A Japanese Patent Application No. 2007-30728

  In order to solve the above problems, the present invention provides a magnetic transfer master body and a magnetic transfer master capable of maintaining the vertical symmetry of the transfer waveform without changing the L / S ratio of the magnetic pattern at the time of fine processing of the magnetic transfer master body. An object of the present invention is to provide a method for manufacturing a magnetic recording medium, a magnetic recording medium on which a magnetic pattern is formed by a magnetic transfer master body, and a magnetic recording apparatus using the magnetic recording medium.

  According to a first aspect of the present invention, there is provided a magnetic transfer master body for forming a magnetic pattern on a magnetic recording medium using a magnetic transfer method, wherein the substrate of the magnetic transfer master body facing the magnetic recording medium is formed. A pattern recess corresponding to the magnetic pattern on the surface portion, a first magnetic body held in the pattern recess, and a boundary portion between the substrate and the first magnetic body disposed on the pattern recess in the surface portion And a second magnetic body made of a material different from that of the substrate, the saturation magnetization being smaller than the saturation magnetization of the first magnetic body. .

  FIG. 1 shows an embodiment of a magnetic transfer master body according to the present invention. The a) plan view is a view of the surface where the magnetic transfer master body is brought close to or in close contact with a magnetic recording medium (not shown) as viewed from above, and as a cross-sectional view, b) a cross-sectional view taken along line A-A '. The surface 11-1 of the magnetic transfer master body in the figure is a surface in contact with the surface of the magnetic recording medium to which the magnetic pattern including the servo pattern is transferred, and the magnetic transfer master body substrate 11 made of silicon, glass, Ni, etc. A pattern recess 11-2 having a desired cross-sectional shape corresponding to the transfer pattern is provided, the first magnetic body 12 made of FeCo material of high permeability magnetic body is embedded, and b near the magnetic transfer master body surface 11-1 is embedded. ) A Ni or NiFe material, for example, is disposed as the second magnetic body 13 at the boundary portion between the magnetic transfer master body substrate 11 and the first magnetic body 12 in the AA ′ sectional view. When Ni is used as the magnetic transfer master body substrate 11, a NiCo alloy other than Ni is used as the second magnetic body 13.

  Here, the surface of the first magnetic body 12 appears on the surface 11-1 of the magnetic transfer master body, and the second magnetic body 13 surrounds the outside thereof. The shape of the first magnetic body 12 appearing on the surface 11-1 of the magnetic transfer master body is preferably a rectangle, a square, or a shape close to a trapezoid as shown in FIG. The shape of the portion appearing on the surface 11-1 of the magnetic transfer master is preferably similar to the shape of the first magnetic body 12, respectively.

  As described above, the magnetic transfer master body is formed on the side of the magnetic transfer master body substrate 11 made of a material such as silicon, glass, ceramics, or nickel, which is in contact with the magnetic recording medium to which the servo pattern is transferred, by a thin film formation technique. The first magnetic body 12 made of a high magnetic permeability material such as FeCo or CoNi is formed on the surface of the magnetic transfer master body surface 11-1 in accordance with the servo pattern to be transferred to the magnetic recording medium. One end appears with the same height as the surface of the magnetic transfer master body substrate 11, and is on the outside thereof. B) The second magnetic body 13 is located on the shoulder corresponding to the shoulder of the first magnetic body 12 in the AA ′ sectional view. Is formed to fill.

  With such a configuration, for example, when magnetic transfer is performed on a perpendicular magnetic recording type magnetic recording medium in which the magnetization direction of the servo pattern is perpendicular to the surface 11-1 of the magnetic transfer master body shown in the figure, the magnetic transfer master body of the present invention is used. When perpendicularly applied magnetic transfer is performed using a magnetic transfer master waveform, the transfer magnetic field waveform on the medium after perpendicularly applied magnetic transfer obtains a pattern close to a vertically symmetrical shape in which the magnetic field strength is almost equal in both forward and reverse directions. Can do.

  FIG. 4 shows an example of a simulation result of a transfer magnetic field waveform in a magnetic recording medium after perpendicularly applied magnetic transfer using the magnetic transfer master body according to the present invention. FIG. 4 is obtained using the finite element method.

Thus, by using a magnetic material in which the saturation magnetization M _S1 of the first magnetic body 12 in FIG. 1 is larger than the saturation magnetization M _S2 of the second magnetic body, the magnetic transfer according to the present invention of FIG. As shown in the example of the simulation result of the transfer magnetic field waveform on the medium after the perpendicularly applied magnetic transfer using the master body, a substantially symmetrical transfer magnetic field waveform is obtained.

That is, with the conventional L / S ratio adjustment alone, there is a case in which vertical asymmetry occurs in the transfer magnetic field waveform due to the difference in the pitch of the first magnetic body 12. in 11-1 near the portion of the first magnetic body 12 in contact with the magnetic transfer master member substrate 11, the shoulder portion of the so-called first magnetic body 12, than the saturation magnetization M _S of the first magnetic body 12 By embedding a small second magnetic body, the magnetic field at both ends of the upper waveform recess in the figure, which is a feature of the vertical asymmetric waveform shown in FIG. 3, is reduced, and the pitch of the first magnetic body 12 is different. Regardless of this, a substantially symmetrical waveform can be obtained.

This is around the soft magnetic material disclosed in the previous Japanese Patent Application No. 2007-30728 (Patent Document 2), by placing a lower soft magnetic saturation magnetization M _S A still another soft magnetic material The edge portion of the first magnetic body that is in contact with the magnetic recording medium of the magnetic transfer master body is relieved of the concentration of magnetic flux due to the presence of the second magnetic body, and at the same time, the tip of the first magnetic body This is because the width of the upper waveform in the transfer magnetic field waveform can be prevented from being widened even by the difference in the pitch of the first magnetic body 12.

  Here, in b) AA ′ cross-sectional view, the shape of the shoulder portion of the first magnetic body 12 where the second magnetic body 13 is disposed may be a triangle, a shape close to a rectangle, etc. Preferably, a triangle with the tip of the boundary between the magnetic transfer master body surface 11-1 and the first magnetic body 12 as the apex and the boundary with the magnetic transfer master body substrate 11 as the bottom is preferable. The boundary line between the second magnetic body 13 and the first magnetic body 12 may be a straight line or a curved line.

  In this way, when perpendicularly applied magnetic transfer is performed by applying a conventional magnetic transfer master body, the transfer magnetic field waveform in a perpendicular magnetization type magnetic disk medium after perpendicularly applied magnetic transfer is, for example, shown in FIG. The transfer waveform is shifted due to the vertical asymmetry as described above and the pitch of the first magnetic body 12 is different. However, when vertical magnetic transfer is performed by applying the magnetic transfer master body according to the present invention. The transfer magnetic field waveform in the obtained perpendicular magnetization type magnetic disk medium after perpendicularly applied magnetic transfer is a transfer magnetic field waveform as shown in FIG. 4 regardless of the difference in the pitch of the first magnetic body 12. It has been found that on-track control of the head can be performed using a perpendicular magnetization type magnetic recording medium to which a servo signal is transferred by applying the magnetic transfer master body according to the present invention.

  According to the magnetic transfer master body of the first aspect, since the vertical symmetry of the transfer waveform can be maintained without changing the L / S ratio of the magnetic pattern, stable magnetic transfer can be performed on the magnetic recording medium to be magnetically transferred. A magnetic transfer master body can be provided.

Needless to say, the magnetic transfer master body according to the present invention can be used not only for magnetic transfer to a perpendicular magnetic recording type magnetic recording medium but also for magnetic transfer to an in-plane magnetic recording type magnetic recording medium. .
The invention according to claim 2 of the present invention is a method of manufacturing a magnetic transfer master body in which a magnetic pattern is formed on a magnetic recording medium using a magnetic transfer method. A step of providing a pattern recess corresponding to the magnetic pattern, a step of providing a first magnetic body in the pattern recess, a saturation magnetization smaller than the saturation magnetization of the first magnetic body, and a material different from that of the substrate And a step of disposing a second magnetic body on at least a portion of the surface portion of the substrate and the boundary portion of the first magnetic body disposed in the pattern recess. It is a manufacturing method of a body.

  According to the second aspect of the present invention, it is possible to manufacture a magnetic transfer master body for obtaining a magnetic recording medium having a more uniform upper and lower waveform of the magnetic transfer magnetic field.

  According to a third aspect of the present invention, there is provided a magnetic recording medium on which a magnetic pattern corresponding to the magnetic pattern of the magnetic transfer master body according to the first aspect is formed.

  According to the third aspect of the present invention, in both the in-plane magnetic recording system and the perpendicular magnetic recording system, the head tracking control with good quality can be performed by the servo pattern formed by the magnetic transfer apparatus according to the present invention. it can. The magnetic recording medium according to claim 3 may be a magnetic recording medium in which a magnetic pattern is formed by the magnetic transfer master body according to claim 1 and this is used as a servo pattern. Includes a magnetic recording medium in which the servo pattern is additionally written or the servo pattern is rewritten based on the magnetic pattern.

  According to a fourth aspect of the present invention, there is provided a magnetic recording apparatus using the magnetic recording medium according to the third aspect. The magnetic recording medium according to claim 4 of the present invention may be a magnetic recording medium fixed to the magnetic recording apparatus or a magnetic recording medium removable from the magnetic recording apparatus.

  For the magnetic material embedded in the magnetic transfer master body, the second magnetic material having a saturation magnetization Ms smaller than that of the first magnetic body is disposed in the portion corresponding to the shoulder of the surface of the first magnetic body. It is possible to improve forward and reverse asymmetry of the magnetic field strength distribution applied to the medium to be transferred.

  FIG. 2 shows an embodiment of the manufacturing procedure of the magnetic transfer master body according to the present invention. 2A to 2D are sectional views of the magnetic transfer master body in a plane perpendicular to the surface of the magnetic transfer master body facing a magnetic recording medium (not shown) to be magnetically transferred. Show.

  Below, a manufacturing procedure is demonstrated in order.

  1) The magnetic transfer master body substrate is etched so that the resist pattern is undercut.

  2A, a magnetic transfer master body substrate 21 is made of, for example, a Si substrate having a flat surface, and a resist pattern 22 corresponding to the shape of the servo pattern is formed on the surface of the Si substrate by an EB exposure method or a nanoimprint method. Form. Thereafter, the servo pattern engraved on the resist pattern 22 is transferred to the magnetic transfer master body substrate 21 by dry etching the magnetic transfer master body substrate 21 in an undercut manner to form a pattern recess 21-1.

    For example, when an induction plasma type RIE apparatus is used as an example of the dry etching conditions, the gas pressure when using SF6 or CF4 as the gas species is 5.0 Pa, which is higher than that of normal anisotropic etching. To do. Further, the RF power is 300 W, and the pattern concave portion 21-1 is formed in the magnetic transfer master body substrate 21. The remaining resist pattern 22 is left on the magnetic transfer master body substrate 21.

  2) Sputter deposition of FeCo with resist remaining.

  Further, a first magnetic body made of FeCo material is deposited on the pattern recess 21-1 by sputtering. As shown in FIG. 2B, the deposition amount is such that the top of the FeCo 23 deposited on the pattern recess 21-1 protrudes from the plane of the magnetic transfer master body substrate 21 and does not protrude from the upper end surface of the pattern recess 21-1. And

  3) Residual resist is removed by lift-off.

  As shown in FIG. 2-3, by performing lift-off, FeCo 23 on the resist pattern 22 and FeCo remaining on the surface of the magnetic transfer master body substrate 21 are removed.

  4) NiFe is embedded in the gaps of the pattern recesses by plating to flatten the pattern recesses.

  As shown in FIG. 2-4, for example, a second magnetic body made of NiFe is embedded in the space between the pattern recesses 21-1 by plating, and the surface of the magnetic transfer master body substrate 21 is flattened by chemical polishing by CMP. . In addition to the method of embedding Ni in the gaps of the recesses by plating, the surface of the magnetic transfer master body substrate 21 may be planarized by chemical polishing by CMP after depositing Ni by vapor deposition or sputtering.

  The magnetic transfer master body substrate 21 has been described as an example in which a Si substrate having a flat surface is used. However, in addition to the Si substrate, a substrate made of a material such as glass or ceramics can also be used.

FeCo23 is made of FeCo material, but may be a high permeability material such as CoNi.
Furthermore, after the surface of the magnetic transfer master substrate 21 is flattened, a lubricating layer may be provided on the surface facing the magnetic recording medium to be magnetically transferred, or a lubricant may be applied.

  FIG. 4 shows a simulation result of the transfer magnetic field waveform in the magnetic recording medium after the magnetic transfer perpendicularly applied to the magnetic recording medium using the magnetic transfer master body produced by the above method. The up-and-down asymmetry of the magnetic field strength appearing in the transfer magnetic field waveform of the magnetic recording medium magnetically transferred by the conventional magnetic transfer master body shown in FIG. 3 is eliminated in FIG.

Here, the materials of the first magnetic body and the second magnetic body satisfying the relationship of M _S1 > M _S2 between the saturation magnetization M _S1 of the first magnetic body and the saturation magnetization M _S2 of the second magnetic body are used. It was found that the symmetry of the transfer magnetic field waveform was improved by using it. Further, when the coercivity of the first magnetic body is H _C1 , the coercivity of the second magnetic body is H _C2 , and the magnetic transfer magnetic field is H _dup , the first satisfying the relationship of H _C1 <H _dup <HC ₂ The symmetry of the transfer magnetic field waveform is further improved by using the magnetic material and the material of the second magnetic material and magnetizing the second magnetic material in the direction opposite to the transfer direction in advance before the magnetic transfer. I also understood that.

  FIG. 5 shows an example of a magnetic transfer apparatus according to the present invention. In the figure, only the main part of the magnetic transfer apparatus is shown, and other parts use known techniques. a) In the figure before magnetic transfer, the holder 51 with a rotating shaft for a magnetic transfer master body has a convex portion at the center portion made of, for example, stainless steel, and has a hole in the center portion of the magnetic transfer master body 52 according to the present invention. A magnetic transfer master body 52 according to the present invention is attached as a guide.

  The magnetic transfer master body 52 is fixed to the surface of the magnetic transfer master body-attached rotary shaft holder 51 by a vacuum suction mechanism (not shown) provided in the magnetic transfer master body-attached rotary shaft holder 51. The surface portion of the magnetic transfer master body 52 has a magnetic transfer pattern 52-1 provided with a magnetic body corresponding to the servo pattern in the concave portion of the magnetic transfer master body 52.

  A holder 53 with a rotating shaft for a magnetic recording medium supported by a position adjusting mechanism (not shown) for adjusting the inclination in the three axis directions of the XYZ axes and the Z axis direction which is the vertical direction in the figure is used for a magnetic transfer master body. Similarly to the holder 51 with a rotating shaft, the magnetic recording medium 54 is fixed to the surface of the holder 53 with a rotating shaft for a magnetic recording medium by a vacuum suction mechanism (not shown) provided in the holder 53 with a rotating shaft for a magnetic recording medium. The position adjustment mechanism adjusts the tilt in the XY axis direction (perpendicular to the drawing surface of the drawing) and the Z axis direction with respect to the magnetic transfer master body 52 so that the surfaces of the magnetic transfer master body 52 and the magnetic recording medium 54 are in close contact with each other. At a close distance, b) First held as shown in the magnetic transfer diagram.

  The adjustment in the XY-axis direction is performed, for example, by control by a position adjustment mechanism that makes the misalignment between the holder 51 with a rotating shaft for a magnetic transfer master body and the holder 53 with a rotating shaft for a magnetic recording medium zero. The inclination of the direction is adjusted in advance on the surface of the magnetic transfer master body 52 fixed to the magnetic recording medium rotating shaft holder 53 by its own weight with the magnetic recording medium rotating shaft holder 53 to which the magnetic recording medium 54 is fixed. The inclination of the holder 53 with the rotating shaft for the magnetic recording medium when placed is used as a reference.

  Furthermore, in the figure of b) magnetic transfer, in the state where the surfaces of the magnetic transfer master body 52 and the magnetic recording medium 54 are held in close contact or close to each other, the holder 51 with a rotating shaft for the magnetic transfer master body and the magnetic recording medium The holder 53 with a rotation shaft rotates in the same direction at a desired rotation speed.

  The electromagnet 55 moves in the horizontal direction at a desired speed while applying a preset magnetic field in the vertical direction on the upper surface of the magnetic recording medium rotating shaft-equipped holder 53. Here, wiring for supplying a current to the electromagnet 55 is omitted in the drawing.

Here, it is assumed that the magnetic recording medium 54 has been initialized. That is, when the magnetic recording medium 54 is a perpendicular magnetic recording type magnetic recording medium, initialization is performed so that the magnetization directions of the magnetic recording medium 54 are all aligned in the downward direction of the figure, for example. b) In view of the magnetic transfer, in the absence of a magnetic transfer master body 52, while applying a magnetic field of more than twice the coercivity H _c of the magnetic recording medium 54 in a constant orientation in the vertical direction by electromagnets 55, the desired speed To move the electromagnet 55 in the horizontal direction. The magnetization direction of the magnetic recording layer of the magnetic recording medium 54 is set to the vertical direction (for example, downward in the figure).

Next, as shown in the figure of b) magnetic transfer, the magnetic transfer pattern 52-1 provided on the magnetic transfer master body 52 for magnetic transfer of the servo pattern exists on the initialization surface of the magnetic recording medium 54. After the surfaces are brought into close contact with each other, the current flowing through the electromagnet 55 is reversed from the initialization direction, and a magnetic field in the opposite direction is applied to transfer the servo pattern to the magnetic recording medium 54.
In the figure, the magnetization direction of the portion of the magnetic recording medium 54 corresponding to the tip of the magnetic material in the present invention in the portion that appears as a small black spot in the magnetic transfer pattern 52-1 is reversed, and the servo pattern is formed on the magnetic recording medium 54. Transcribed. Magnetic field strength in this case is, for example, the same and the coercive force H _c of the magnetic recording medium 54.

  Here, in the example of the magnetic transfer apparatus according to the present invention in FIG. 5, initialization is performed in order to clarify the contrast of the servo pattern, but this initialization is not always necessary.

  FIG. 6 shows an example of a magnetic disk device according to the present invention. FIG. 3 is a perspective view of the inside of a magnetic disk device with a cover covering the magnetic disk device omitted for explanation. In FIG. 6, a spindle motor (not shown) for rotating and supporting a disk 61 is attached to the base 60 of the magnetic disk apparatus, and the disk 61 is fixed to a disk rotating shaft 62 of the spindle motor.

  The disk 61 uses a magnetic recording medium on which a servo pattern is magnetically transferred by a magnetic transfer device according to the present invention. The disk 61 may be a longitudinal magnetic recording type magnetic recording medium or a perpendicular magnetic recording type magnetic recording medium.

  A head 63 provided with a recording / reproducing element for writing information to and reading information from the disk 61 is attached to, for example, a suspension 64 obtained by processing a spring steel plate made of stainless steel, and the suspension 64 is made of a metal arm. It is attached to the tip of 65-3. Here, an FPC (not shown) that relays the exchange of signals with the recording / reproducing element is firmly attached to and integrated with the suspension 64 via the adhesive layer on the surface of the suspension 64.

  Here, it goes without saying that the head 63 is a type of head applicable to the disk 61 depending on whether the disk 61 is a magnetic recording medium of the in-plane magnetic recording system or a magnetic recording medium of the perpendicular magnetic recording system.

  The arm 65-3 is fixed to the rotary shaft 65-2 of the actuator 65 that swings the arm 65-3 to the left and right, and with respect to the tip of the arm 65-3 to which the suspension 64 is attached and the rotary shaft 65-2. A coil (not shown) is attached to the rear end on the opposite side.

  As a current flows through the coil attached to the arm 65-3 in the magnetic field generated from the magnetic circuit 65-1, the arm 65-3 moves to the left and right depending on the direction of the flowing current around the rotation shaft 65-2. By swinging, the head 63 is positioned on a desired track 61-2 on the surface of the disk 61.

  An FPC 4-3 is connected from the actuator 65 to a circuit board (not shown) mounted on the back surface of the base 60, and sends and receives control signals and drive current. Further, a connector part 66 for connection with an external device is provided on the base 60.

  In the figure, an area having a servo pattern magnetically transferred by the magnetic transfer apparatus according to the present invention is shown as a servo area 61-1 for the track 61-2.

  Here, the servo pattern in the servo area 61-1 may be magnetically transferred by the magnetic transfer device according to the present invention, or may be transferred by the head 63 based on the magnetic pattern transferred by the magnetic transfer device according to the present invention. It may be of the added type.

  The magnetic recording medium according to the present invention is incorporated in the magnetic disk drive having the above-described configuration, and the servo in the servo area 61-1 necessary for accurately positioning the head 63 on the track 61-2. Since the state of the magnetization distribution of each reverse magnetization region in the pattern is the above-described preferable state, it can be used as a signal for good positioning control.

  Here, although the fixed disk is used in the example of the magnetic disk apparatus in FIG. 5, the magnetic disk apparatus may be a disk apparatus using a cartridge type disk.

1 shows an embodiment of a magnetic transfer master body according to the present invention. An example of the manufacturing procedure of the magnetic transfer master body according to the present invention will be described. An example of a transfer magnetic field waveform simulation result in a magnetic recording medium after perpendicularly applied magnetic transfer using a conventional magnetic transfer master body is shown. The example of the simulation result of the transfer magnetic field waveform in the magnetic recording medium after perpendicularly applied magnetic transfer using the magnetic transfer master body according to the present invention is shown. 1 shows an example of a magnetic transfer apparatus according to the present invention. 1 shows an example of a magnetic disk device according to the present invention. An example of a sectional view of a conventional magnetic transfer master body is shown. An example of a transfer magnetic field waveform calculated by simulating a case where the pitch is changed with the master pattern unevenness ratio = 3.1 is shown.

Explanation of symbols

11 Magnetic transfer master body substrate 12 First magnetic body 13 Second magnetic body 21 Magnetic transfer master body Si substrate 22 Resist pattern 23 FeCo
24 Ni
51 Magnetic transfer master body holder with rotating shaft 52 Magnetic transfer master body 53 Magnetic recording medium holder with rotating shaft 54 Magnetic recording medium 55 Electromagnet 60 Base 61 Disk 62 Disk rotating shaft 63 Head 64 Suspension 65 Actuator 66 Connector portion

Claims (4)

A magnetic transfer master body for forming a magnetic pattern on a magnetic recording medium using a magnetic transfer method, wherein a pattern recess corresponding to the magnetic pattern is formed on a surface portion of the substrate of the magnetic transfer master body facing the magnetic recording medium. ,
A first magnetic body held in the pattern recess,
The substrate is disposed on at least a portion of the surface portion of the substrate and the boundary portion of the first magnetic body disposed in the pattern recess, and the saturation magnetization is smaller than the saturation magnetization of the first magnetic body, and the substrate And a second magnetic body made of a different material from the magnetic transfer master body. A method of manufacturing a magnetic transfer master body that forms a magnetic pattern on a magnetic recording medium using a magnetic transfer method,
Providing a pattern recess corresponding to the magnetic pattern on the surface of the substrate of the magnetic transfer master body;
Providing a first magnetic body in the pattern recess;
A second magnetic body having a saturation magnetization smaller than that of the first magnetic body and having a material different from that of the substrate is disposed on the surface portion of the first magnetic body and the substrate. And a step of disposing at least a part of the boundary portion of the body.   A magnetic recording medium having a magnetic pattern corresponding to the magnetic pattern of the magnetic transfer master body according to claim 1.   A magnetic recording apparatus using the magnetic recording medium according to claim 3.

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