JP2001028124A - Magnetic transferring method and magnetic transferring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transfer a high grade transfer pattern by magnetic transfer from its master carrier to a slave medium without depending on a position of a magnetic pattern. SOLUTION: The magnetic transferring method is such that a pair of electromagnets 8a-8b, 8c-8d are arranged in two pairs, each consisting of two single electromagnets having a magnetic field symmetrically in respect to an axis of a magnetic pole, with the like-poles faced oppositely, with a slave medium 4 held in between and with the axis of the magnetic pole positioned perpendicular to the slave medium 4 face; that the two pairs of electromagnets 8a-8b, 8c-8d are arranged in the manner that the polarity is different between the adjacent electromagnets; that, by rotating the slave medium 4 or two pairs of the electromagnets 8a-8d in a track direction and by applying a magnetic field in the track direction of the slave medium face, after the slave medium magnetization is preliminarily initial-DC-magnetized in the track direction, a magnetic transfer master carrier and the initial DC magnetized slave medium 4 are closely stuck together; and that magnetic transfer is performed by applying the transfer magnetic field in the track direction opposite to the initial-DC-magnetizing direction of the slave medium 4 face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recording a large amount of information at a time on a magnetic recording medium,
The present invention relates to a method for transferring recorded information to a magnetic recording medium having a high recording density.

[0002]

2. Description of the Related Art The amount of information handled by personal computers and the like has been dramatically increased due to the progress of use of digital images and the like. Due to the increase in the amount of information, there is a demand for a large-capacity, inexpensive magnetic recording medium for recording information and a short recording and reading time. High-density recording media such as hard disks, ZIP
In a high-density floppy (registered trademark) disk-type magnetic recording medium represented by (Iomega Co., Ltd.), the information recording area is composed of narrow tracks as compared with a general floppy disk. In order to scan the head and perform signal recording and reproduction at a high S / N ratio, it is necessary to perform accurate scanning using tracking servo technology.

Therefore, in a large-capacity magnetic recording medium such as a hard disk or a removable magnetic recording medium, a tracking servo signal, an address information signal, a reproduction clock signal, and the like are recorded at intervals within one rotation of the disk. The so-called pre-format has been done. The magnetic head can read the preformatted signal and correct its own position to accurately travel on the track.

The current preformat is manufactured by recording disks one by one and one track by using a dedicated servo recording device. There is a problem that the servo recording device is expensive, and it takes a long time to manufacture the preformat, so that it takes a long time to manufacture, which also affects the manufacturing cost.

There has also been proposed a method of performing magnetic transfer without preformatting one track at a time. For example, JP-A-63-183623, JP-A-10-4
Japanese Patent No. 0544 and Japanese Patent Application Laid-Open No. 10-269566 introduce a transfer technique. However, in the magnetic transfer method, no practical proposal has been made, including the conditions of the magnetic field applied during transfer and specific means for generating the magnetic field.

As a recording method for solving such a conventional problem, Japanese Unexamined Patent Publication (Kokai) No. 63-183623 and Japanese Patent Laid-Open Publication No. 10-45544 disclose a method of forming a concavo-convex shape corresponding to an information signal on the surface of a substrate. The surface of the magnetic transfer master carrier in which the ferromagnetic thin film is formed on at least the convex surface of the uneven shape is brought into contact with the surface of the sheet-shaped or disk-shaped magnetic recording medium on which the ferromagnetic thin film or the ferromagnetic powder coating layer is formed, Alternatively, a method has been proposed in which an AC bias magnetic field or a DC magnetic field is applied to excite a ferromagnetic material forming the surface of a convex portion, thereby recording a magnetization pattern corresponding to the uneven shape on a magnetic recording medium.

According to this method, the surface of the convex portion of the magnetic transfer master carrier is brought into close contact with a magnetic recording medium to be preformatted, that is, a slave medium, and at the same time, the ferromagnetic material constituting the convex portion is excited to form the slave medium. This is a method by transfer to form a predetermined format. Recording can be performed statically without changing the relative position between the magnetic transfer master carrier and the slave medium, and accurate preformat recording is possible. It has the feature of. In addition, the time required for recording is very short. That is, in the method of recording from the above-described magnetic head, there is a problem that usually several minutes to several tens of minutes are required, and the time required for transfer becomes longer in proportion to the recording capacity. In this case, the transfer can be completed in one second or less regardless of the recording capacity and the recording density.

Referring to FIG. 1, transfer of a preformat pattern on a magnetic transfer master carrier will be described. FIG. 1A is a plan view schematically illustrating a magnetic layer surface of a magnetic transfer master carrier, and FIG. 1B is a cross-sectional view illustrating a transfer process. In a predetermined area of a track of the magnetic transfer master carrier 1, a preformat area 2 and a data area 3 in which patterns of a tracking servo signal and an address signal to be transferred are formed are formed. The preformat information can be transferred as recording information 7 to the slave medium side by applying a transfer external magnetic field 6 in the track direction 5 by bringing the slave medium 4 into close contact with the slave medium 4, so that the slave medium can be manufactured efficiently. Can be done. However, it has been clarified that when the transfer is performed by such a method, the information signal quality may be poor, and the servo operation may be inaccurate in some cases.

[0009]

SUMMARY OF THE INVENTION According to the present invention, the servo operation of a slave medium manufactured by transferring a preformat pattern by applying an external magnetic field while closely adhering a magnetic transfer master carrier and a slave medium becomes inaccurate. It is an object of the present invention to provide a stable transfer method and apparatus by preventing such a situation.

[0010]

According to the present invention, a master carrier for magnetic transfer, in which a magnetic layer is formed at a portion corresponding to an information signal on the surface of a substrate, is brought into close contact with a slave medium comprising a magnetic recording medium to be transferred. In the magnetic transfer method of applying a transfer magnetic field, a single electromagnet having a magnetic field symmetrical to the axis of the magnetic pole is formed by opposing the same poles with the magnetic pole axis perpendicular to the slave medium surface with the slave medium interposed therebetween. Two pairs of the arranged electromagnets are arranged next to each other so that the adjacent electromagnets have different polarities, and the slave medium or the two pairs of electromagnets are rotated in the track direction to apply a magnetic field in the track direction on the slave medium surface. By performing the initial DC magnetization of the slave medium magnetization in the track direction in advance, the master carrier for magnetic transfer and the slave medium with the initial DC magnetization are brought into close contact with each other, and the A magnetic transfer method for performing magnetic transfer by applying a transfer magnetic field in the track direction of the initial DC magnetization opposite to the direction of the medium surface. A magnetic transfer method in which a magnetic transfer master carrier having a magnetic layer formed on a portion corresponding to an information signal on the surface of the substrate and a slave medium made of a magnetic recording medium to be transferred are brought into close contact with each other, and a transfer magnetic field is applied.
A magnetic field is applied in the track direction of the slave medium surface, the magnetization of the slave medium carrier is initially DC-magnetized in the track direction, and then a single electromagnet having a magnetic field symmetrical to the axis of the magnetic pole is moved to the master carrier for magnetic transfer. And a pair of electromagnets having the same polarity facing each other with the contact body perpendicular to the surface of the contact body where the slave medium is in close contact with the slave medium. This is a magnetic transfer method in which a pair of electromagnets or a magnetic transfer master carrier and a close contact body of a slave medium are rotated in the track direction, and a transfer magnetic field in a track direction opposite to the initial DC magnetization direction is applied to perform magnetic transfer.

A pair of single electromagnets having a magnetic field symmetrical to the axis of the magnetic pole are arranged such that the axis of the magnetic pole is opposed to the poles of the magnetic transfer master carrier and the slave medium, with the poles perpendicular to the surface of the adhesive body. The magnetic field intensity distribution in the track direction of the magnetic field generated when two pairs of the electromagnets are arranged adjacent to each other so that the adjacent electromagnets have different polarities has a magnetic field intensity portion greater than the coercive force _{Hcs of the} slave medium in the track direction position. Wherein the magnetic transfer method has at least one or more locations. A single electromagnet having a magnetic field symmetrical to the axis of the magnetic pole, a pair of electromagnets with the axis of the magnetic pole perpendicular to the slave medium surface with the same poles facing each other with the slave medium interposed, and the polarity of adjacent electromagnets is different As described above, the magnetic field intensity distribution in the track direction of the magnetic field generated when two pairs are arranged adjacent to each other has a magnetic field intensity portion greater than the coercive force _Hcs of the slave medium in only one direction at the track direction position, The magnetic field strength in the opposite direction is determined by the coercive force H of the slave medium at any position in the track direction.
_The above magnetic transfer method, wherein the magnetic transfer method is less than _cs .

A pair of electromagnets having a single electromagnet having a magnetic field symmetrical to the axis of the magnetic pole and having the axis of the magnetic pole perpendicular to the surface of the slave medium and having the same poles opposed to each other with the slave medium interposed therebetween,
In the track direction magnetic field strength distribution of the magnetic field generated when two pairs are arranged adjacently so that the polarities of adjacent electromagnets are different, a magnetic field strength exceeding the maximum value of the optimum transfer magnetic field strength range exists at any position in the track direction. However, there is at least one or more magnetic field strengths within the optimum transfer magnetic field strength range in one track direction, and the magnetic field strength in the opposite track direction is the optimum transfer magnetic field strength at any position in the track direction. The above magnetic transfer method, wherein the magnetic transfer method is less than the minimum value of the range. Optimal transfer magnetic field intensity, 0.6 × Hcs~1.3 × Hc respect coercivity H _cs of the slave medium
s is the magnetic transfer method described above.

Also, a magnetic transfer master carrier having a magnetic layer formed on a portion corresponding to an information signal on the surface of the substrate and a slave medium composed of a magnetic recording medium to be transferred are brought into close contact with each other to apply a transfer magnetic field. In the transfer device, a single electromagnet having a magnetic field symmetrical to the axis of the magnetic pole is formed by a pair of electromagnets arranged with the magnetic pole axis perpendicular to the slave medium surface with the same poles facing each other with the slave medium interposed therebetween. The two pairs of magnets are arranged adjacent to each other so that the polarities are different, and the slave medium or two pairs of electromagnets are rotated in the track direction, and a magnetic field is applied in the track direction of the slave medium surface, thereby preliminarily tracking the slave medium magnetization. Initial DC magnetizing means for initial DC magnetization in the direction, adhesion means for bringing the master medium for magnetic transfer into close contact with the slave medium having the initial DC magnetized, A magnetic transfer apparatus comprising a transfer magnetic field applying means for applying a transfer magnetic field to the initial DC magnetization opposite to the direction of the track direction of the medium surface. In a magnetic transfer apparatus for applying a transfer magnetic field by closely adhering a magnetic transfer master carrier having a magnetic layer formed on a portion corresponding to an information signal on the surface of a substrate and a slave medium made of a magnetic recording medium to be transferred, Initial DC magnetizing means for applying a magnetic field in the track direction of the medium surface and initial DC magnetizing the slave medium magnetization in the track direction in advance, adhesion means for bringing the master medium for magnetic transfer into close contact with the initial DC magnetized slave medium, and a magnetic pole axis. A single electromagnet having a symmetric magnetic field and a pair of electromagnets arranged with the magnetic pole axis perpendicular to the slave medium surface and with the same poles facing each other with the close contact body of the slave medium and the magnetic transfer master carrier interposed, Two pairs are arranged adjacent to each other so that the polarity of the electromagnets to be driven is different, and the slave medium or the two pairs of electromagnets are rotated in the track direction, and A magnetic transfer apparatus having a magnetic transfer means for applying the track direction transfer magnetic field in the magnetization direction and opposite.

A pair of electromagnets having a single electromagnet having a magnetic field symmetrical with respect to the axis of the magnetic pole and having the axis of the magnetic pole perpendicular to the surface of the slave medium and having the same polarity facing each other with the slave medium interposed therebetween are:
A magnetic field intensity distribution in the track direction of a magnetic field generated when two pairs are arranged adjacent to each other so that adjacent electromagnets have different polarities has at least one magnetic field intensity portion in the track direction at least _{equal to} the coercive force _{Hcs of the} slave medium. The above magnetic transfer apparatus has the above. A pair of electromagnets having a single electromagnet having a magnetic field symmetrical to the axis of the magnetic pole, with the axis of the magnetic pole perpendicular to the surface of the slave medium, and with the same poles facing each other with the close contact body between the slave medium and the master carrier for magnetic transfer The magnetic field strength distribution in the track direction of the magnetic field generated when two pairs are arranged adjacently so that the polarities of the adjacent electromagnets are different, the magnetic field strength part of the coercive force _Hcs or more of the slave medium at the track direction position. In the above magnetic transfer device, the magnetic transfer device has only one direction, and the magnetic field intensity in the opposite direction is less than the coercive force _Hcs of the slave medium at any position in the track direction.

A pair of electromagnets having a single electromagnet having a magnetic field symmetrical with respect to the axis of the magnetic pole and having the axis of the magnetic pole perpendicular to the surface of the slave medium and having the same polarity facing each other with the slave medium interposed therebetween,
In the track direction magnetic field strength distribution of the magnetic field generated when two pairs are arranged adjacently so that the polarities of adjacent electromagnets are different, a magnetic field strength exceeding the maximum value of the optimum transfer magnetic field strength range exists at any position in the track direction. However, at least one portion having a magnetic field strength within the optimum transfer magnetic field strength range exists in one track direction, and the magnetic field strength in the opposite track direction is the optimum transfer magnetic field strength in any track direction position. The magnetic transfer device according to the above, wherein the intensity is less than the minimum value of the intensity range. 0.6 × optimal transfer magnetic field intensity with respect to the coercive force H _cs of the slave medium Hcs~1.3 × Hcs
The magnetic transfer device described above.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present inventors have found that when a transfer magnetic field is applied from the outside while a magnetic transfer master carrier and a slave medium are brought into close contact with each other, a portion where transfer is unstable and signal quality is reduced is generated. The present inventors have found that the reason is that the signal quality is degraded due to an inappropriate magnetic field applied at the time of transfer, and have arrived at the present invention.

In the magnetic transfer from the magnetic transfer master carrier to the slave carrier, when an external magnetic field higher than the coercive force _Hcs of the slave medium is applied, all the magnetization states of the slave are magnetized in the applied direction. It was generally thought that a pattern to be originally transferred was not recorded. For example, Japanese Patent Application Laid-Open No. 10-45544 also describes in paragraph 0064 that it is preferable that the holding force be equal to or less than the coercive force of the magnetic recording medium. However, according to the study of the present inventors, the principle of magnetic transfer in this method is as shown in FIG. 1, in which the transfer magnetic layer portion of the magnetic transfer master carrier 1 substantially in contact with the slave medium 4 is used. The external magnetic field 6 becomes a magnetic field 6 a absorbed by the convex portion, and does not have a magnetic field strength that can be recorded in the magnetic layer of the slave medium 4 in contact, but does not contact the slave medium 4 of the magnetic transfer master carrier 1. The magnetic layer of the slave medium 4 corresponding to the concave portion has a recordable magnetic field intensity, and is magnetized in the direction of the transfer external magnetic field 6 as shown in FIG. It has been found that the information can be transferred to the medium 4 as the recording information 7. Therefore, during the transfer from the magnetic transfer master carrier to the slave medium, the portion in contact with the slave medium has a large amount of magnetic field entering the pattern portion of the magnetic transfer master carrier, so that the slave medium is not protected. It is considered that even if a transfer magnetic field higher than the magnetic force _Hcs is applied, the transfer is not reversed.
Then, by applying a transfer magnetic field having a specific relationship strength as compared with the coercive force _{Hcs of the} slave medium, a slave medium with high signal quality can be obtained.

In order to realize clear transfer in any pattern, the slave medium is _subjected to initial DC magnetization with a sufficiently large magnetic field in one direction and a coercive force _Hcs or more, preferably 1.2 times _Hcs or more. A transfer magnetic field having a specific strength, that is, a magnetic field in an optimum transfer magnetic field strength range is applied. A preferable transfer magnetic field is 0.6 × H _cs ≦ transfer magnetic field ≦ 1.3 × H _cs . The direction is applied in a direction opposite to the direction of the initial DC magnetization. Also, transfer magnetic field is more preferably 0.8～1.2H _cs, more preferably 1 to 1.
Is a 1H _cs.

The magnetic recording medium for performing servo preformatting is a disk-shaped recording medium in which information is recorded along tracks concentrically drawn from the center of rotation. In such a disk-shaped magnetic recording medium, a magnetic field application method of transferring a radial pattern is performed by applying a magnetic field in the track direction of the slave medium surface, that is, in the tangential direction of the circular arc at an arbitrary track direction position, and then preliminarily tracks the slave medium magnetization. Initial DC magnetization in the direction.

Next, the master carrier for magnetic transfer is brought into close contact with the slave medium which has been subjected to the initial DC magnetization, and a transfer magnetic field is applied in the track direction on the surface of the slave medium to perform magnetic transfer. It is necessary that the direction of the initial DC magnetization and the transfer magnetic field applied for performing the magnetic transfer are opposite to each other on the slave medium surface.

Therefore, in order to apply a magnetic field under the above-mentioned applied magnetic field condition over the entire surface of the disk-shaped medium, a magnetic field intensity distribution such that at least one magnetic field intensity portion of the slave medium having a coercive force _Hcs or more in the track direction position is provided. Is generated in a part of the track direction, and the slave medium or the magnetic field is rotated one turn in the track direction to realize the initial DC magnetization.

Further, the coercive force H _cs or more field intensity portion of the slave medium in track direction position has in only one direction, the opposite direction of the magnetic field strength coercivity than Hcs of the slave medium at any track direction position By generating a magnetic field having a magnetic field intensity distribution as described above in a part of the track direction and rotating the slave medium or the magnetic field once in the track direction, a magnetic field for initial DC magnetization of the slave medium magnetization in the track direction is applied in advance. be able to.

There is no magnetic field strength exceeding the maximum value of the optimum transfer magnetic field strength range at any track direction position, and at least one portion having the magnetic field strength within the optimum transfer magnetic field strength range in one track direction is provided. A magnetic field having a magnetic field intensity distribution such that the magnetic field intensity in the opposite track direction is less than the minimum value of the optimum transfer magnetic field intensity range at any position in the track direction is generated in a part of the track direction. It can also be realized by applying a transfer magnetic field in the track direction of the slave medium surface by rotating the master carrier and the initial DC magnetized slave carrier in the track direction while keeping them close together, or by rotating the magnetic field in the track direction. it can.

The electromagnet used for initial DC magnetization and magnetic transfer preferably has a size approximately equal to or greater than the distance from one end track to the other end track of the slave medium. In the case of the slave medium, it is preferable that the slave medium has a size approximately equal to or larger than the radial distance from the outermost track to the innermost track of the slave medium. By using the one having such a size, only the slave medium, the close contact body between the slave medium and the master carrier for magnetic transfer, or the electromagnet is moved in one direction over the entire length of the track or rotated only once. It is possible to apply a uniform magnetic field to the slave medium surface. In addition, the intensity of the magnetic field applied by using an electromagnet is required to be uniform at all track positions, and the magnitude of the variation is preferably within ± 5% at all track positions, and more preferably within ± 2.5%. Is more preferred.

In the transfer method and the transfer apparatus of the present invention, since an electromagnet is used as a magnet, the distance between the electromagnet and the slave medium or the inclination of the slave medium with respect to the slave medium surface can be reduced when the initial DC magnetization or transfer magnetic field is applied. By adjusting the exciting current value supplied to the electromagnet in addition to the adjustment, the intensity of the magnetic field acting on the slave medium can be adjusted, and the magnetic transfer using the slave medium having various coercive forces and the magnetic transfer master carrier can be performed. It becomes possible.

A transfer method and a transfer device will be described below with reference to the drawings. FIG. 2 is a diagram illustrating a method of applying a magnetic field in which two pairs of electromagnets are arranged adjacent to each other with the slave medium interposed therebetween perpendicular to the slave medium surface. FIG.
(A) shows a pair of electromagnets 8a and 8b having a magnetic field symmetrical with respect to the axis of the magnetic pole on the upper and lower surfaces of the slave medium 4.
And a pair of electromagnets 8c and 8d are further arranged so that the same type of magnetic poles are opposed to each other, and the adjacent magnetic poles have the opposite polarity. An example in which the slave medium 4 is rotated in such a state is shown, and a DC exciting current is given to the electromagnets 8a, 8b, 8c, 8d from DC power supplies 9a, 9b, 9c, 9d, respectively.

Since the single electromagnets 8a and 8b are arranged on the upper and lower surfaces of the slave medium 4 with the same poles facing each other, the magnetic fields of 8a and 8b repel each other as shown in FIG. Then, the magnetic field of the electromagnet 8a is directed to the electromagnet 8c of the other pair of adjacent electromagnets.
The magnetic field b is the electromagnet 8 of the other pair of adjacent electromagnets.
A magnetic field toward d is generated, and a magnetic field 10 is applied to the surface of the slave medium 4.

FIG. 2C is a diagram showing the magnetic field intensity applied to the slave medium. The magnetic field applied to the slave medium has a peak 11 exceeding the coercive force _Hcs of the slave medium.
Exists, and the slave medium can be initially DC-magnetized by rotating the slave medium or rotating the electromagnet. The distance between the opposing electromagnets arranged adjacent to each other is set such that the magnetic field formed by the adjacent electromagnets can give the slave carrier a magnetic field having a strength equal to or higher than the coercive force of the slave carrier. Good.

FIG. 3 is a diagram for explaining a method of transferring from a magnetic transfer master carrier to a slave medium. FIG. 3 (A)
FIG. 3B is a diagram for explaining the application of a magnetic field to the adhered body between the slave medium and the master carrier for magnetic transfer, and FIG. 3B illustrates the strength of the magnetic field given by the application of the magnetic field in FIG. FIG. On the upper and lower surfaces of the contact body 12 in which the slave medium 4 is in close contact with the magnetic transfer master carrier 1,
A pair of electromagnets 8 having a magnetic field symmetric with respect to the axis of the magnetic pole
a and 8b are arranged such that magnetic poles of the same type are opposed to each other, and electromagnets 8c and 8d are arranged adjacent thereto so that adjacent magnetic poles have opposite polarities. An example in which the close contact body 12 is rotated in such a state is shown.

Since the same poles are arranged opposite to the single electromagnets 8a and 8b provided on the upper and lower surfaces of the contact body 12, the magnetic fields of the electromagnets 8a and 8b repel each other,
The magnetic field of the electromagnet 8a is, of the other pair of adjacent electromagnets,
The magnetic field of the electromagnet 8b is directed to the electromagnet 8c, and a magnetic field is directed to the electromagnet 8d of the other pair of adjacent electromagnets.

FIG. 3B is a diagram showing the magnetic field intensity applied to the slave medium that is in close contact with the magnetic transfer master carrier. Since the peak 14 having a small intensity in the magnetic field applied to the slave medium is much smaller than the optimum transfer magnetic field intensity range, it does not affect the transfer of the pattern from the magnetic transfer master carrier to the slave medium. Only peak 15 having a large value contributes to magnetic transfer. In addition, it is possible to form a good pattern irrespective of the shape of the pattern by applying a magnetic field included in the optimum transfer magnetic field intensity range from the magnetic transfer master carrier to the slave medium at the peak 15 having a large intensity.

The apparatus used in the magnetic transfer method shown in FIGS. 2 and 3 is provided with a mechanism capable of arbitrarily adjusting the distance between the slave medium surface and the electromagnet and the distance between a pair of adjacent electromagnets. By adjusting the distance between the slave medium and the electromagnet and the distance between the pair of electromagnets, a desired magnetic field strength can be obtained on the slave medium surface. As the type of the electromagnet, either an air-core type solenoid coil or a type having a core such as an iron core at the center can be used.

The method for producing the magnetic transfer master carrier used in the magnetic transfer of the present invention will be described. As a substrate for a magnetic transfer master carrier, a non-magnetic metal or alloy such as silicon, quartz plate, glass, and aluminum, a ceramic, a synthetic resin, or the like is a plate-like body having a smooth surface, and is used in etching and film forming processes. What has resistance to processing environments, such as temperature, can be used.

A photoresist is coated on a substrate having a smooth surface, and is exposed and developed using a photomask corresponding to the pattern of the preformat, or the photoresist is preformatted by a method such as directly scribed. A pattern corresponding to the information is formed.

Next, in the etching step, the substrate is etched according to the pattern by an etching means suitable for the substrate such as reactive etching, physical etching using argon plasma, etching using a liquid, or the like. The depth of the hole formed by etching is set to a depth corresponding to the thickness of the magnetic layer formed as the transfer information recording portion, and is preferably 20 nm or more and 1000 nm or less. If the thickness is too large, the spread width of the magnetic field increases, which is not desirable.

The hole to be formed is preferably a hole having a uniform depth such that the bottom surface is formed by a plane parallel to the surface of the substrate. The hole preferably has a rectangular cross section in the track direction perpendicular to the surface.

Next, the magnetic material is vacuum-deposited by vacuum deposition, sputtering, ion plating, or the like.
A magnetic material is formed up to the surface of the substrate with a thickness corresponding to the hole formed by the plating method. The magnetic characteristics of the transfer information recording section are as follows: the coercive force (Hc) is 199 kA / m (2500 Oe).
Hereinafter, preferably 0.4 to 119 kA / m (5 to 150 kA / m).
0 Oe), and the saturation magnetic flux density (Bs) is 0.
It is 3T (tesla) or more, preferably 0.5T or more.
Next, the photoresist is removed by a lift-off method, and the surface is polished to remove any flash, and the surface is planarized.

In the above description, a method of forming a hole in a substrate and forming a magnetic material in the formed hole has been described. However, a magnetic material is formed in a predetermined position on the substrate by a photofabrication method. After forming the projections of the transfer information recording portion and, between the projections, a non-magnetic material is deposited or filled,
The surface of the transfer information recording section and the surface of the non-magnetic material section may be coplanar.

As a magnetic material that can be used for the magnetic layer, cobalt, iron, or an alloy thereof having a high magnetic flux density can be used. Specifically, Co,
CoPtCr, CoCr, CoPtCrTa, CoPt
CrNbTa, CoCrB, CoNi, Fe, FeC
o, FePt and the like. The thickness of the magnetic layer is 20 to 1000 nm, preferably 30 to 500 nm. If it is too thick, the recording resolution decreases.

In particular, it is clear that the magnetic flux density is high and the magnetic medium has magnetic anisotropy in the same direction as the slave medium, for example, in the in-plane direction for in-plane recording and in the perpendicular direction for perpendicular recording. It is preferable for the transfer to be performed. It is preferable that the magnetic material has fine magnetic particles or an amorphous structure in that a sharp edge can be formed.

In order to form the magnetic material with magnetic anisotropy, it is preferable to provide a non-magnetic underlayer, and it is necessary that the crystal structure and lattice constant are the same as those of the magnetic layer. Specifically, as such an underlayer, C
r, CrTi, CoCr, CrTa, CrMo, NiA
1, Ru, or the like can be formed by sputtering.

Further, a protective film such as a diamond-like carbon film may be provided on the magnetic layer, and a lubricant may be provided. More preferably, a 5 to 30 nm diamond-like carbon film and a lubricant are present as a protective film. The reason why it is necessary to provide a lubricant thereon is that friction occurs when correcting a displacement occurring in the process of contact with the slave, and durability is insufficient without a lubricant layer.

The magnetic transfer master carrier of the present invention can be used not only for transferring magnetically recorded information to a disk-type magnetic recording medium such as a hard disk or a large-capacity removable magnetic recording medium, but also for a card-type magnetic recording medium or a tape-type magnetic recording medium. It can also be used to transfer magnetically recorded information to a medium.

[0044]

The present invention will be described below with reference to examples. Example 1 and Comparative Example 1 (Preparation of Magnetic Transfer Master Carrier) In a vacuum film forming apparatus, the pressure was reduced to 1.33 × 10 ⁻⁵ Pa (10 ⁻⁷ Torr) at room temperature, and argon was introduced thereinto. 0.4 Pa (3 × 1
0 ^-3 Torr) on a silicon substrate.
An FeCo film having a thickness of 0 nm was formed to obtain a 3.5-type disk-shaped master carrier for magnetic transfer. Coercive force Hc is 8 kA / m
(100 Oe), and the magnetic flux density Ms is 28.9T (2300T).
0 Gauss). Radial lines of 10μ width from the center of the disk to the position of 20mm to 40mm in the radial direction from the center of the disk.
At the innermost peripheral position of 10 μm.

(Preparation of Slave Medium) In a vacuum film forming apparatus, the pressure was reduced to 1.33 × 10 ⁻⁵ Pa (10 ⁻⁷ Torr) at room temperature, and then argon was introduced to obtain 0.4 Pa (3 × 10 ⁻⁵ Pa).
Under a condition of 10 ⁻³ Torr, the glass plate was heated to 200 ° C., and CoCrPt 25 nm, Ms: 5.7 T (450
0Gauss), the coercive force H _cs: 199kA / m (250
A 3.5-inch disk-shaped magnetic recording medium (0 Oe) was produced.

(Initial DC magnetization method) The coercive force _Hcs of the slave medium is set such that the peak magnetic field intensity is at the surface of the slave medium.
The electromagnet was arranged as shown in FIG. 2 so as to be twice as high as 388 kA / m (5000 Oe), and the initial DC magnetization of the slave medium was performed.

(Magnetic Transfer Test Method) The slave medium which was initially DC-magnetized and the magnetic transfer master carrier were brought into close contact with each other.
Using a device having electromagnets on both surfaces shown in FIG. 3, magnetic transfer was performed by applying a voltage in the direction opposite to the magnetization of the slave medium. The close contact between the master carrier for magnetic transfer and the slave medium was pressed from above the aluminum plate with the rubber plate interposed.

(Electromagnetic Conversion Characteristic Evaluation Method) The transfer signal of the slave medium was evaluated by an electromagnetic conversion characteristic measuring device (SS-60 manufactured by Kyodo Electronics). In the head, a reproducing head gap: 0.35 μm, a reproducing track width: 3.1 μm,
Recording head gap: 0.4 μm, recording track width:
A 3.0 μm MR head was used. The read signal is frequency-decomposed by a spectroanalyzer, and the difference between the peak intensity (C) of the primary signal and the extrapolated medium noise (N) (C /
N) was measured. Of the C / N at each magnetic field strength, the maximum value was set to 0 dB, and the relative value (△ C / N) was evaluated.
It was shown to. When the C / N value is -20 dB or less, the signal quality of the magnetic transfer is not at a practical level, and is indicated by *.

[0049]

Table 1 H _{cs of} slave medium 199 kA / m Ratio to peak intensity kA / m Hcs of transfer magnetic field ΔC / N (dB) 59.7 0.3 * 99.5 0.5 -16.8 119 0.6 -3.2 159 0.8 -1.5 179 0.9 -0.3 199 1.0 0.0 219 1.1 -0.1 239 1.2 -2.1 259 1.3 -3.8 279 1.4-10.2 298 1.5 -19.9 318 1.6 * 398 2.0 *

The slave medium of Example 2 and Comparative Example 2 coercivity H _cs is 199kA / m (2500Oe), the peak magnetic field strength 239 kA / m (3000
Oe), that is, the coercive force _Hcs of the slave medium is 1.2.
Example 1 except that the initial DC magnetization of the slave medium was performed at twice the magnetic field strength, and then the magnetic transfer was performed by closely contacting the initial DC-magnetized slave medium and the magnetic transfer master carrier.
After magnetic transfer was performed in the same manner as in Example 1, the measurement was performed in the same manner as in Example 1. The results are shown in Table 2. The peak intensity of the transfer magnetic field indicates the peak of the magnetic field intensity distribution shown in FIG.

[0051]

Table 2 H _{cs of} slave medium 199 kA / m Ratio of peak intensity of transfer magnetic field to kA / m Hcs ΔC / N (dB) 59.7 0.3 * 99.5 0.5 -10.6 119 0.6-5.2 159 0.8-1.2 179 0.9 0.0 199 1.0-0.6 219 1.1-0.7 239 1.2-2.3 259 1.3 -2.9 279 1.4 -9.6 298 1.5 -18.4 318 1.6 * 398 * 2.0 *

[0052] slave medium in Comparative Example 3 coercivity H _cs is 199kA / m (2500Oe), the peak magnetic field strength 159 kA / m (2000
Oe), that is, 0.8 of the coercive force _Hcs of the slave medium.
Example 1 except that the initial DC magnetization of the slave medium was performed at twice the magnetic field strength, and then the magnetic transfer was performed by closely contacting the initial DC-magnetized slave medium and the magnetic transfer master carrier.
After performing the magnetic transfer in the same manner as in Example 1, the measurement was performed in the same manner as in Example 1. The results are shown in Table 3. The peak intensity of the transfer magnetic field indicates the peak of the magnetic field intensity distribution in FIG.

[0053]

[Table 3] H _{cs of} slave medium 199 kA / m Ratio to peak intensity kA / m Hcs of transfer magnetic field ΔC / N (dB) 59.7 0.3 * 99.5 0.5 * 119 0.6 * 159 0.8 * 179 0.9 * 199 1.0 * 219 1.1 * 239 1.2 * 259 1.3 * 279 1.4 * 298 1.5 * 318 1.6 * 398 2.0 *

[0054] Example 3 and Comparative Example 4 Example 1 coercivity H _cs which was prepared in the same manner as is 159kA
A slave medium / m (2000 Oe), the peak magnetic field strength 318 kA / m (4000 Oe), i.e. perform initial DC magnetization of the slave medium at twice the field strength of H _cs coercivity of the slave medium, then initial DC The magnetic transfer was performed in the same manner as in Example 1 except that the magnetized slave medium and the master carrier for magnetic transfer were brought into close contact with each other, and magnetic transfer was performed using the apparatus shown in FIG. The measurement was performed in the same manner, and the results are shown in Table 4. The peak intensity of the transfer magnetic field indicates the peak of the magnetic field intensity distribution in FIG.

[0055]

TABLE 4 slave medium H _cs 159 kA / m ratio of the peak intensity kA / m Hcs of transfer magnetic field △ C / N (dB) 47.7 0.3 * 79.6 0.5 -16.3 95 5.5 0.6 -2.6 127 0.8 -2.3 143 0.9 -0.2 159 1.0 0.0 175 1.1 -0.3 191 1.2 -0.9 207 1 0.3-3.1 223 1.4 -12.3 239 1.5 -16.9 255 1.6 1.6 * 318 2.0 *

[0056] peak magnetic field strength to the slave medium of Example 4 and Comparative Example 5 coercivity H _cs is 159kA / m (2000Oe) is 191kA / m (2400O
e) In other words, the initial DC magnetization of the slave medium was performed in the same manner as in Example 4 except that the initial DC magnetization of the slave medium was performed at a magnetic field strength 1.2 times the coercive force _Hcs of the slave medium. After magnetic transfer was performed with the master carrier in close contact with the master carrier, measurement was performed in the same manner as in Example 1. The results are shown in Table 5. The peak intensity of the transfer magnetic field indicates the peak of the magnetic field intensity distribution in FIG.

[0057]

Table 5 slave medium H _cs 159 kA / m ratio of the peak intensity kA / m Hcs of transfer magnetic field △ C / N (dB) 47.7 0.3 * 79.6 0.5 -16.3 95 5.5 0.6 -2.2 127 0.8 -0.8 143 0.9 0.0 159 1.0 -0.2 175 1.1 -0.3 191 1.2 -3.8 207 1 0.3-5.9 223 1.4-9.6 239 1.5-18.2 255 255 1.6 * 318 2.0 *

[0058] Comparative Example 6 Example 1 coercivity H _cs which was prepared in the same manner as is 159kA
A slave medium / m (2000 Oe), the peak magnetic field strength 127 kA / m (1600 Oe), i.e. perform initial DC magnetization of the slave medium at 0.8 times the magnetic field strength H _cs coercivity of the slave medium, then Fig. 3 shows the initial DC magnetized slave medium and the magnetic transfer master carrier
After magnetic transfer was performed in the same manner as in Example 1 except that magnetic transfer was performed using the apparatus shown in Table 1, measurement was performed in the same manner as in Example 1, and the results are shown in Table 6. The peak intensity of the transfer magnetic field indicates the peak of the magnetic field intensity distribution in FIG.

[0059]

[Table 6] slave medium H _cs 159 kA / m magnetic field for transfer ratio of the peak intensity kA / m Hcs of △ C / N (dB) 47.7 0.3 * 79.6 0.5 * 95.5 0 6.6 * 127 0.8 * 143 0.9 * 159 1.0 * 175 1.1 * 191 1.2 * 207 1.3 * 2231.4 * 2391.5 * 2551.6 * 3182 0.0 *

[0060]

According to the present invention, in magnetic transfer from a magnetic transfer master carrier to a slave medium, a high-quality transfer magnetic field having a specific strength is applied to _Hcs of the slave medium, thereby achieving high quality regardless of the position and shape of the pattern. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining transfer of a preformat pattern on a magnetic transfer master carrier.

FIG. 2 is a diagram illustrating a method of applying a magnetic field using an electromagnet in which two pairs of electromagnets are arranged adjacent to each other with a slave medium interposed therebetween perpendicular to the slave medium surface.

FIG. 3 is a diagram for explaining a method of transferring from a magnetic transfer master carrier to a slave medium.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Master carrier for magnetic transfer, 2 ... Preformatted area, 3 ... Data area, 4 ... Slave medium, 5 ... Track direction, 6 ... External magnetic field for transfer, 6a ... Magnetic field absorbed by a convex part, 7 ... Recording information , 8a, 8b, 8c, 8d: electromagnets, 9a, 9b, 9c, 9d: DC power supply, 10: magnetic field,
11 ... peak, 12 ... adhered body, 13 ... transfer magnetic field, 14 ...
Small intensity peak, 15 ... High intensity peak

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shoichi Nishikawa 2-1-1, Ogimachi, Odawara-shi, Kanagawa Prefecture Fuji Photo Film Co., Ltd. F-term (reference) 5D112 AA05 BB01 FA02

Claims (12)

[Claims] 1. A magnetic device for applying a transfer magnetic field by closely adhering a magnetic transfer master carrier having a magnetic layer formed on a portion corresponding to an information signal on a surface of a substrate and a slave medium comprising a magnetic recording medium to be transferred. In the transfer method, a single electromagnet having a magnetic field symmetrical to the axis of the magnetic pole, a pair of electromagnets arranged with the magnetic pole axis perpendicular to the slave medium surface with the same poles facing each other across the slave medium, Two pairs are arranged adjacently so that the electromagnets have different polarities, and the slave medium or the two pairs of electromagnets are rotated in the track direction to apply a magnetic field in the track direction on the slave medium surface, thereby preliminarily setting the slave medium magnetization. After the initial DC magnetization in the track direction, the master medium for magnetic transfer and the slave medium with the initial DC magnetization are brought into close contact with each other, and the initial DC magnetization direction of the slave medium surface is A magnetic transfer method comprising: performing a magnetic transfer by applying a transfer magnetic field in a reverse track direction. 2. A transfer magnetic field is applied by closely adhering a magnetic transfer master carrier having a magnetic layer formed on a portion corresponding to an information signal on a surface of a substrate and a slave medium made of a magnetic recording medium to be transferred. In the magnetic transfer method, a magnetic field is applied in the track direction of the slave medium surface, and the slave medium carrier magnetization is initially DC-magnetized in the track direction in advance, and then a single electromagnet having a magnetic field symmetrical to the axis of the magnetic pole is moved to the axis of the magnetic pole. A pair of electromagnets arranged with the same poles facing each other with the contact body perpendicular to the contact body surface where the master carrier and the slave medium are in close contact with each other, and two pairs are arranged adjacent to each other so that the polarities of the adjacent electromagnets are different. A pair of electromagnets or a master body for magnetic transfer and a contact body of the slave medium are rotated in the track direction, and a transfer magnetic field in the track direction opposite to the initial DC magnetization direction is applied. And performing magnetic transfer. 3. A single electromagnet having a magnetic field symmetric with respect to the axis of the magnetic pole is disposed with the axis of the magnetic pole facing the same pole perpendicularly to the surfaces of the magnetic transfer master carrier and the slave medium with the contact body interposed therebetween. The magnetic field strength distribution in the track direction of a magnetic field generated when two pairs of the paired electromagnets are disposed adjacent to each other so that the polarities of the adjacent electromagnets are different from each other tracks the magnetic field strength portion greater than the coercive force _{Hcs of the} slave medium. 2. The magnetic transfer method according to claim 1, wherein the magnetic transfer method has at least one position in the direction position. 4. A single electrode having a magnetic field symmetrical about the axis of the pole.
The magnet is set so that the axis of the magnetic pole is perpendicular to the slave medium plane.
A pair of electromagnets with the same poles facing each other across
Two adjacent pairs so that the polarities of adjacent electromagnets are different
In the track direction of the magnetic field generated when
The field strength distribution is determined by the coercive force H of the slave medium. _csMore magnetic field strength
It has a degree part only in one direction at the track direction position,
The magnetic field strength in the opposite direction is
Coercive force H of probe medium_csLess than
Item 6. The magnetic transfer method according to Item 1. 5. A pair of electromagnets each having a single electromagnet having a magnetic field symmetric with respect to the axis of the magnetic pole and having the axis of the magnetic pole perpendicular to the surface of the slave medium and having the same polarity facing each other with the slave medium interposed therebetween, In the track direction magnetic field strength distribution of the magnetic field generated when two pairs are arranged adjacently so that the electromagnets have different polarities, no magnetic field strength exceeding the maximum value of the optimum transfer magnetic field strength range exists at any track direction position. There is at least one or more magnetic field strengths within the optimum transfer magnetic field strength range in one track direction, and the magnetic field strength in the opposite track direction is the optimum transfer magnetic field strength range at any track direction position. 3. The magnetic transfer method according to claim 2, wherein the value is less than the minimum value. 6. The optimum transfer magnetic field strength, magnetic transfer method according to claim 5, characterized in that a 0.6 × Hcs~1.3 × Hcs with respect to the coercive force H _cs of the slave medium. 7. A magnetic field for applying a transfer magnetic field by closely adhering a magnetic transfer master carrier having a magnetic layer formed at a portion corresponding to an information signal on a surface of a substrate and a slave medium comprising a magnetic recording medium to be transferred. In the transfer device, a single electromagnet having a magnetic field symmetrical to the axis of the magnetic pole is formed by a pair of electromagnets arranged with the magnetic pole axis perpendicular to the slave medium surface with the same poles facing each other with the slave medium interposed therebetween. By disposing two pairs adjacent to each other with different polarities, rotating the slave medium or two pairs of electromagnets in the track direction, and applying a magnetic field in the track direction on the slave medium surface,
Initial DC magnetizing means for initial DC magnetization of the slave medium magnetization in the track direction in advance, adhesion means for bringing the master medium for magnetic transfer into close contact with the initial DC magnetized slave medium, and tracks opposite to the initial DC magnetization direction of the slave medium surface A magnetic transfer apparatus comprising a transfer magnetic field applying means for applying a transfer magnetic field in a direction. 8. A magnetic field for applying a transfer magnetic field by closely adhering a magnetic transfer master carrier having a magnetic layer formed on a portion corresponding to an information signal on a surface of a substrate and a slave medium comprising a magnetic recording medium to be transferred. In the transfer device, an initial DC magnetizing means for applying a magnetic field in the track direction of the slave medium surface to initially DC magnetize the slave medium magnetization in the track direction in advance, and an adhesion means for bringing the master medium for magnetic transfer and the initial DC magnetized slave medium into close contact with each other. , A single electromagnet having a magnetic field symmetrical to the axis of the magnetic pole, and a pair of magnets arranged with the magnetic pole axis perpendicular to the slave medium surface with the same poles facing each other with the close contact body between the slave medium and the magnetic transfer master carrier interposed therebetween Two pairs of electromagnets are arranged next to each other so that adjacent electromagnets have different polarities, and the slave medium or two pairs of electromagnets are rotated in the track direction. And a magnetic transfer unit for applying a transfer magnetic field in a track direction opposite to the initial DC magnetization direction. 9. A pair of electromagnets each having a single electromagnet having a magnetic field symmetric with respect to the axis of the magnetic pole and having the axis of the magnetic pole perpendicular to the surface of the slave medium and having the same polarity facing each other with the slave medium interposed therebetween, The magnetic field strength distribution in the track direction of the magnetic field generated when two pairs are arranged adjacently so that the polarities of the electromagnets are different has at least one magnetic field strength portion at the track direction position that is higher than the coercive force _{Hcs of the} slave medium. The magnetic transfer apparatus according to claim 7, wherein: 10. A single electromagnet having a magnetic field symmetric with respect to the axis of a magnetic pole, with the axis of the magnetic pole perpendicular to the surface of the slave medium and with the same poles facing each other with the close contact body of the slave medium and the magnetic transfer master carrier interposed therebetween. A magnetic field intensity distribution in a track direction of a magnetic field generated when two pairs of the arranged electromagnets are arranged adjacent to each other so that the polarities of the adjacent electromagnets are different from each other has a magnetic field intensity portion _larger than the coercive force _Hcs of the slave medium. _8. The magnetic transfer according to claim 7, wherein the magnetic field intensity is less than the coercive force _Hcs of the slave medium at any position in the track direction. apparatus. 11. A pair of electromagnets each having a single electromagnet having a magnetic field symmetric with respect to the axis of a magnetic pole and having the axis of the magnetic pole perpendicular to the surface of the slave medium and having the same polarity facing each other with the slave medium interposed therebetween, In the track direction magnetic field strength distribution of the magnetic field generated when two pairs are arranged adjacently so that the electromagnets have different polarities, no magnetic field strength exceeding the maximum value of the optimum transfer magnetic field strength range exists at any track direction position. The magnetic field intensity within the optimum transfer magnetic field strength range exists in at least one location in one track direction, and the magnetic field strength in the opposite track direction is the optimum transfer magnetic field strength range at any position in the track direction. 9. The magnetic transfer device according to claim 8, wherein the value is less than the minimum value. 12. The optimum transfer magnetic field strength is a magnetic transfer apparatus according to claim 11, characterized in that a 0.6 × Hcs~1.3 × Hcs with respect to the coercive force H _cs of the slave medium.