JP2002117533A - Master carrier for magnetic transfer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transfer a high-quality signal to a slave medium when magnetic transfer is carried out by making a magnetic transfer master carrier and the slave medium tightly adhere to each other, and applying a transfer magnetic field. SOLUTION: This magnetic transfer master carrier used for magnetic transfer carried out by making the magnetic transfer master carrier and a slave medium tightly adhere to each other is constructed in such a manner that a projected part corresponding to a transfer information signal is formed on the surface, and the roughness of the part of a boundary between a recessed part and the projected part is set to be equal to 20 nm or lower by Ra value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for magnetically transferring information recorded on a magnetic recording medium for a large-capacity, high-recording-density magnetic recording / reproducing apparatus. The present invention relates to a magnetic transfer method used for recording servo signals, address signals, and other ordinary video signals, audio signals, data signals, and the like.

[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 large-capacity removable magnetic recording medium such as (Iomega) and Hi-Fd (Sony), the information recording area is composed of narrow tracks as compared with a floppy (registered trademark) disk, and a narrow track width is required. In order to accurately scan the magnetic head and perform signal recording and reproduction at a high S / N ratio, it is necessary to perform accurate scanning using a tracking servo technique.

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 provided at a constant angular interval with respect to one rotation of the disk. A recorded area is provided, and the magnetic head reproduces these signals at regular intervals to accurately scan the track while confirming and correcting the position of the head. A method of recording these signals on a magnetic recording medium in advance is called a preformat when the magnetic recording medium is manufactured. Accurate positioning accuracy is required for recording of servo signals for tracking, address information signals, reproduced clock signals, etc.After the magnetic recording medium is incorporated in the drive, the position is strictly controlled using a dedicated servo recording device. Preformat recording is performed by the magnetic head.

However, in the preformat recording of the servo signal, the address information signal, and the reproduction clock signal by the magnetic head, since the recording is performed while strictly controlling the position of the magnetic head using a dedicated servo recording device, it is necessary to perform one recording. Each of these is manufactured by recording one track at a time, and it takes a long time to perform preformat recording. Further, as the magnetic recording density increases, the amount of signals to be preformat-recorded increases, which requires a longer time. Therefore, in the manufacture of a magnetic recording medium, the ratio of the cost required for the preformat recording process of servo signals and the like to the manufacturing cost increases, and it is desired to reduce the cost in this process.

On the other hand, there has also been proposed a system in which preformat information is recorded by magnetic transfer from a master carrier to a slave medium without recording the preformat information one track at a time. For example, JP-A-63-183623, JP-A-10-40544 and JP-A-10-2695
No. 66 introduces a transfer technique. JP-A-63-
In the method described in Japanese Patent Application Laid-Open No. 183623/1998 or Japanese Patent Application Laid-Open No. 10-45544, an irregular shape corresponding to an information signal is formed on the surface of a substrate as a magnetic transfer master carrier, and a ferromagnetic thin film is formed on at least the convex surface of the irregular shape. The surface of the formed magnetic transfer master carrier is brought into contact with the surface of a sheet-shaped or disk-shaped magnetic recording medium on which a coating layer of a composition containing a ferromagnetic thin film or a ferromagnetic powder is formed, or further, an AC bias magnetic field, Alternatively, by applying a DC magnetic field to excite the ferromagnetic material constituting the surface of the convex portion, a magnetization pattern corresponding to the irregular shape is recorded on the magnetic recording medium.

In this method, the surface of a convex portion of a 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, a ferromagnetic material constituting the convex portion is excited to form a slave medium. This is a transfer method for forming a record of predetermined preformat information, which allows static recording to be performed without changing the relative position between the magnetic transfer master carrier and the slave medium. The feature is that it is possible and the time required for recording is extremely short.

Further, since this magnetic transfer method is a method in which both the magnetic transfer master carrier and the slave medium are brought into contact with each other in a stationary state and the transfer is performed, both the magnetic transfer master carrier and the slave medium are used in the servo signal recording step. This is a method in which damage is less likely to occur and high durability is expected.

The pattern of the magnetic transfer master carrier can be formed by a lithography technique or a method similar to the method for producing an optical disk stamper. Especially CD-R
A method of producing a pattern on a photoresist by a laser which is also used for producing a stamper for producing an OM, developing the pattern, and then forming a magnetic transfer master carrier by electroforming, is a method in which a metal base is directly This is an excellent method as a method for manufacturing a magnetic transfer master carrier for transferring to a slave medium. However, when a magnetic transfer master carrier manufactured by such a method is transferred using a slave medium, the quality of a transfer pattern of magnetic recording information transferred to the slave medium may deteriorate. there were.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a master carrier substrate for magnetic transfer having a concave and convex shape corresponding to an information signal formed on the surface of the substrate is brought into close contact with a slave medium to apply a transfer magnetic field to the slave medium. It is an object of the present invention to provide a magnetic transfer master carrier capable of transferring a higher quality magnetic transfer signal when performing magnetic transfer.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic transfer master carrier used for magnetic transfer in which a magnetic transfer master carrier is brought into close contact with a slave medium and a transfer magnetic field is applied. Is formed by a magnetic transfer master carrier having a Ra value of 20 nm or less at the boundary between the concave portion and the convex portion and in contact with the slave medium.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a magnetic transfer master carrier having an uneven shape corresponding to an information signal to be transferred, and a transfer signal boundary portion when transferred to a slave medium. By making the shape of the boundary of the corresponding uneven portion a specific shape, the magnetic recording signal transferred to the magnetic recording medium by the magnetic transfer method was found to be of high quality, And the roughness of the portion in close contact with the slave medium is Ra value of 20 nm.
It has been found that a high-quality pattern can be obtained by the following.

The present invention will be described below with reference to the drawings.
FIG. 1 is a diagram illustrating a magnetic transfer master carrier used in the magnetic transfer method of the present invention. FIG. 1 (A) is a plan view, FIG. 1 (B) is a partial cross-sectional view, FIG. 1 (C)
FIG. 3 is a cross-sectional view illustrating a transfer pattern. FIG.
As shown in FIG. 1A, the servo areas 2 on which the servo signals of the magnetic transfer master carrier 1 are recorded are regularly arranged on the surface of the magnetic recording medium. Thus, the servo area occupies an area of 10% or less, and the other area is the data area 3. As shown in FIG. 1B, when a signal is transferred to form a servo area on the slave medium, if the servo area 2 of the magnetic transfer master carrier 1 is in close contact with the slave medium surface, the data area 3 is transferred. The servo area 2 does not need to be in close contact with the slave medium 4, so that the servo area 2 may be either convex or planar as long as it is in close contact with the slave medium.

In the servo area 2, a transfer pattern 5 corresponding to magnetic recording information to be transferred is formed. During magnetic transfer, magnetic transfer is performed by applying a transfer magnetic field while the transfer pattern 5 is in close contact with the surface of the slave medium 4. The transfer pattern 5 is shown in FIG.
As shown in FIG. 3, a magnetic layer 8 is formed on a convex pattern 7 formed on the base 6 of the magnetic transfer master carrier 1 in accordance with the transfer pattern. When given, a transfer pattern corresponding to the convex pattern is formed on the slave medium corresponding to the magnetic layer.

The magnetic transfer method of the present invention is carried out in a state where the magnetic transfer master carrier and the slave medium are in stationary contact with each other. In this state, only the convex portion of the magnetic transfer master carrier, that is, only the magnetic layer portion is in contact with the slave medium. By applying an external magnetic field, a pattern corresponding to the information signal, which is a pattern of the projections, is transferred to the slave medium. Factors affecting the quality of the transferred signal in the magnetic transfer method of the present invention include: B. Contact state and close contact state between master carrier for magnetic transfer and slave medium B. strength of external magnetic field D. Magnetic properties of the magnetic layer on the master carrier substrate The uniformity of the pattern of the projections on the master carrier substrate can be mentioned.

The factor A is that if magnetic transfer is performed in a state where there is a gap between the two solids, the magnetic transfer does not occur and the magnetic transfer signal is dropped or the leakage magnetic flux in the gap is generated. This is related to a phenomenon that a transferred signal is blurred due to the influence. It is considered that a signal pattern that is most faithful to the original pattern is transferred in a state where there is no gap. Regarding the above factors B and C, the information transferred is determined by the fact that if the external magnetic field is too strong, the leakage flux to the outside of the pattern increases, and if the external magnetic field is too weak, sufficient transfer does not occur even in the portion to be transferred. It is conceivable that the signal pattern is shifted from the original pattern. The present invention relates to the factor D, and under the conditions in which the factors A, B, and C are optimized, as a result of earnestly examining the quality of a signal pattern to be further transcribed to be higher quality, The present invention has been reached.

The master carrier for magnetic transfer and the slave medium are in stationary contact with good adhesion, and when an optimized external magnetic field is applied thereto, the magnetic medium provided on the convex portion of the master carrier for magnetic transfer is provided. It is considered that an information signal having a pattern shape most faithful to the pattern shape of the layer is transferred.
Here, being faithful to the pattern shape of the magnetic layer provided on the convex portion of the magnetic transfer master carrier means that if the pattern of the magnetic layer of the convex portion of the magnetic transfer master carrier is disturbed, the disturbance is also transmitted to the slave. It means that it is transferred to the medium. That is, the quality of the information signal transferred to the slave medium is also governed by the quality of the pattern of the magnetic layer on the convex portion of the magnetic transfer master carrier.

FIG. 2 is a view for explaining a pattern formed on the magnetic transfer master carrier. FIG. 2A is an enlarged plan view showing a part of the magnetic transfer master carrier, and FIG. 2B is a perspective view of the transfer pattern viewed from the A direction. (C) is a diagram for explaining the shape of magnetic information transferred to the slave medium. As shown in FIG. 2 (A), a convex pattern 7 arranged in the track direction 9 is formed in the transfer pattern forming portion on the magnetic transfer master carrier 1 and the direction A in FIG. As shown in the perspective view of FIG. 2B, the boundary 11 between the convex pattern 7 and the concave portion 10 is not linear, and irregularities occur at this portion. As a result, when a transfer magnetic field is applied, an information signal having a pattern shape faithful to the pattern shape of the magnetic layer provided on the convex portion of the magnetic transfer master carrier is transferred, as shown in FIG. 2C. As described above, the transfer information pattern 12 transferred to the slave medium 4 also has the boundary 13 disturbed, and the signal obtained when the transfer information pattern 12 is reproduced by the magnetic head is of low quality.

In order to solve the above problems, the present invention is directed to a magnetic transfer master carrier which has a ridge portion of a convex portion, that is, a portion which is in contact with a slave medium at a boundary portion of irregularities, which is closer to a straight line. And the disturbance of the magnetic field at the boundary between the irregularities is reduced. As a result, the disturbance of the pattern in close contact with the slave medium during transfer is also small,
It is considered that a higher quality information signal pattern can be transferred.

The master carrier for magnetic transfer according to the present invention includes a lithography technique, a pattern cutting technique for an optical disk used for manufacturing a stamper such as a CD-ROM, a technique for injection molding using a master plate having a fine uneven pattern, a photolithography technique, Fabrication is performed by a fabrication technique or the like. Among them, a technique of obtaining a resin substrate by injection molding using an original plate having a fine uneven pattern, or a photofabrication technique can be used.

Next, the magnetic transfer master carrier is replaced with a CD-R.
A method of manufacturing a stamper for manufacturing an OM in the same manner as manufacturing the stamper will be described. Photoresist is applied to a disk-shaped substrate such as quartz or glass with a predetermined surface roughness, and the prebaked photoresist layer is irradiated with laser light modulated according to servo signals while rotating the substrate. Then, a pattern corresponding to a servo signal radially extending from the rotation center in the radial direction for each track is exposed on the photoresist on the entire surface of the disk to a portion corresponding to each servo signal on the circumference, and a baking process is performed after development. .

FIG. 3 is a diagram for explaining a method of forming a pattern by laser irradiation. As shown in FIG. 3A, while rotating the disk-shaped substrate in the track direction 9, a specific radial position corresponding to the pattern forming portion is irradiated with the laser light, and then the laser light is irradiated in the radial direction 14 of the laser light.
The irradiation position of the laser beam 15
By repeating the operation of irradiating a plurality of times, a pattern having a predetermined shape is formed. However, laser light 15
Has an irradiation pattern in a circular shape, so that the end of the trajectory of the adjacent laser light is not linear, and irregularities conforming to the circular shape of the laser light are formed at the boundary of the pattern. In order to reduce the unevenness due to the trajectory of the adjacent laser light, one method is to reduce the diameter of the laser light 15. However, it is difficult to obtain a laser light having such a diameter that the unevenness does not become a problem. There is a problem that a large number of irradiations are required. Therefore, in the present invention, FIG.
As shown in (B), the laser beam 15 is continuously irradiated while scanning in the radial direction 14. If a single pattern of laser light does not form a pattern of a predetermined size, the disk-shaped substrate is rotated in the track direction by an amount corresponding to the width of the laser light, and then irradiated with laser light again. After operating or moving the irradiation position of the laser beam in the track direction, the process of scanning in the radial direction while irradiating the laser beam is repeatedly performed until a pattern of a predetermined size is obtained. According to this method, the end 16 of the pattern to be formed can be linear. Also, irregularities are formed in the radial direction,
When the magnetic transfer information is read from the slave medium, the unevenness in the radial direction does not affect the signal quality.

According to the above method, a thin chemical plating layer such as a silver plating layer is formed by chemical plating on a substrate on which a desired pattern in which the boundary between the irregularities is linear is formed,
Using the chemical plating layer as one electrode, nickel or an alloy thereof is electroformed on the silver plating layer to peel off the metal layer from the substrate to produce a metal plate having a pattern to be formed. Thereafter, a magnetic layer is formed on a metal plate having a pattern corresponding to a signal by a vacuum film forming means. The formation of the magnetic layer can be performed by a vacuum film forming means such as a vacuum evaporation method, a sputtering method, and an ion plating method, and is particularly preferably performed by sputtering. Next, a carbon film such as diamond-like carbon may be formed on the magnetic layer by sputtering or the like. Further, using a metal plate formed by electroforming of nickel as a mold, further electroforming nickel,
A magnetic layer may be formed using the obtained nickel disk as a base of a magnetic transfer master carrier. According to this method, it is possible to form a large number of magnetic transfer master carriers using the metal plate obtained in one pattern forming step as a matrix.

Before forming the magnetic layer, it is preferable to provide a nonmagnetic underlayer on the substrate in order to form a desired magnetic anisotropy, and it is necessary to match the crystal structure and lattice constant to the magnetic layer. It is. Cr, Cr
Ti, CoCr, CrTa, CrMo, NiAl, Ru
Etc. can be used. The thickness of the nonmagnetic underlayer is preferably 200 nm or more and 1000 nm or less, more preferably 300 nm or more and 700 nm or less.

The thickness of the magnetic layer is preferably 50 nm or more and 800 nm or less, more preferably 10 nm or more.
0 nm or more and 500 nm or less. Specifically, as the magnetic layer, Co, a Co alloy (CoNi, CoNiZ) is used.
r, CoNbTaZr, etc.), Fe, Fe alloy (FeC
o, FeCoNi, FeNiMo, FeAlSi, Fe
Al, FeTaN), Ni, Ni alloy (NiFe) can be used. Of these, particularly preferred is F
eCo and FeCoNi. Further, it is preferable to provide a hard carbon protective film such as diamond-like carbon (DLC) on the magnetic layer, and a lubricant layer may be provided on the hard carbon protective film. The protective film preferably has a diamond-like carbon film having a thickness of 5 to 30 nm and a lubricant. The lubricant has an effect of preventing scratches caused by friction when correcting a shift generated in a contact process when the magnetic transfer master carrier and the slave medium are brought into close contact with each other.

The slave medium used in the magnetic transfer method of the present invention may be a magnetic recording medium for a hard disk using a rigid base, or a magnetic recording medium for a floppy disk using a base made of a flexible material. Any of them can be used, and a coating type magnetic recording medium in which ferromagnetic metal particles are dispersed in a binder or a metal thin film type magnetic recording medium in which a ferromagnetic metal thin film is formed on a substrate can be used. Specifically, as a coating type magnetic recording medium, Zi
Zip100, Z which is a recording medium for p (Iomega)
A magnetic recording medium such as ip250 or a high-density floppy disk called HiFD is exemplified.

As a metal thin film type magnetic recording medium, Co, a Co alloy (CoPtCr, CoCr,
CoPtCrTa, CoPtCrNbTa, CoCr
B, CoNi, etc.), Fe, Fe alloys (FeCo, FeP)
t, FeCoNi) can be used. High magnetic flux density, same direction as the magnetic layer of the magnetic transfer master carrier,
That is, it is preferable to have magnetic anisotropy in the in-plane direction for in-plane recording, and to have perpendicular magnetic anisotropy in the case of perpendicular recording because clear transfer can be performed. Further, it is preferable to provide a nonmagnetic underlayer below the magnetic layer, that is, on the substrate side, in order to form a necessary magnetic anisotropy, and it is preferable that the crystal structure and lattice constant match the magnetic layer.

[0027]

The present invention will be described below with reference to examples and comparative examples. Example 1 A photoresist liquid was applied on a glass plate having a smooth surface by spin coating to form a photoresist film having a thickness of 175 nm. The operation of exposing in the radial direction while scanning the laser light in the radial direction on the photoresist film was repeated to form a predetermined pattern. The formation pattern is from the center of the disc to a position of 23 mm to 25 mm in the radial direction,
Radial lines with a width of 0.5 μm, and the distance between the lines is 2 in the radial direction.
It was 2 μm at the innermost peripheral position of 3 mm. Thereafter, the photoresist film is developed, and after removing the exposed portion, the glass plate at the portion where the photoresist film has been removed is etched, and thereafter, the remaining photoresist film is removed, and the glass plate having a concavo-convex pattern is removed. Obtained. Next, a nickel plating layer was formed on the surface of the glass plate and electroforming was performed to obtain a master carrier substrate for magnetic transfer composed of a plating board having an uneven pattern. Next, an FeCo layer (atomic ratio of 70: 3) was formed on the obtained magnetic transfer master carrier substrate.
A magnetic layer composed of 0) was formed in a thickness of 200 nm to obtain a magnetic transfer master carrier. The magnetic layer was formed by a DC sputtering method using a sputtering apparatus (730H manufactured by Anelva), the film formation temperature was 25 ° C., the argon sputtering pressure was 3.3 × 10 ⁻⁴ Pa (0.25 mTorr),
The input power was 2.54 W / cm ² . Next, as a slave medium, a commercially available HiFD disk (coercive force Hc
Uses 199 kA / m (25000 e) and has a peak magnetic field strength of 398 kA / m (5000 Oe: slave Hc).
The initial DC magnetization of the slave medium is performed using an electromagnet device so as to be twice as large as that of the slave medium, and then the slave that has been subjected to the initial DC magnetization is brought into close contact with the master carrier for magnetic transfer, and 199 kA / m (electromagnetic device) is used. Magnetic transfer was performed by applying a magnetic field of 2500 Oe). The slave medium on which the magnetic transfer was performed was evaluated by the following evaluation method, and the magnetic transfer information was evaluated. Table 1 shows the results.

Example 2 A plating board obtained in the same manner as in Example 1 was mounted on an injection molding machine and molded at a temperature of 115 ° C. with a polycarbonate resin (Panlite AD5503, manufactured by Teijin) to obtain a resin substrate. . Further, a magnetic layer was formed on this resin substrate in the same manner as in Example 1 to obtain a magnetic transfer master carrier.
At this time, the line width was 1 μm, and the interval between the lines was 2 μm. The slave medium on which the magnetic transfer was performed was evaluated by the following evaluation method, and the magnetic transfer information was evaluated. Table 1 shows the results.

Comparative Example 1 When exposing a photoresist film by irradiating it with a laser beam,
A master carrier for magnetic transfer was produced in the same manner as in Example 1, except that the operation of scanning the laser beam in the track direction was repeated to expose a pattern having a predetermined shape. The slave medium on which the magnetic transfer was performed was evaluated by the following evaluation method, and the magnetic transfer information was evaluated. Table 1 shows the results.

Comparative Example 2 A master carrier for magnetic transfer was produced in the same manner as in Example 2 except that the plating plate obtained in the same manner as in Comparative Example 1 was used.
The slave medium on which the magnetic transfer was performed was evaluated by the following evaluation method, and the magnetic transfer information was evaluated. Table 1 shows the results.

(Evaluation method) Evaluation of Roughness of Roughness on Roughness of Magnetic Transfer Master Carrier An area of 5 μm × 5 μm in a portion of the prepared magnetic transfer master carrier, which is in contact with the slave medium, at the boundary of the unevenness, was measured with an atomic force microscope (DIGITALINST).
RUMENTS's NANOSCOPE3)
Silicon single crystal probe (NCH type manufactured by Nanosensors)
Scanned in tapping mode using. The obtained measurement image was subjected to image processing to convert the roughness of the boundary portion into X and Y coordinates, and was expressed in Table 1 as Ra-M in units of nm.

2. Evaluation of magnetic transfer signal quality on slave medium Regarding the pattern portion on which the information signal was transferred by magnetic transfer on the slave medium, an area of 5 μm × 5 μm was measured with a magnetic force microscope (MFM: DIGITAL INSTRUUM).
Using NANOSCOPE 3) manufactured by ENTS, Co
Cr-coated silicon single crystal probe (M made by Nocensors)
(ESP type). For signal detection, a frequency modulation method was used. The obtained measurement image was subjected to image processing to convert the roughness of the boundary into X and Y coordinates, and was expressed as Ra-S in Table 1 in nm.

3. Signal distortion The signal distortion of the transfer signal of the slave medium was evaluated using an electromagnetic conversion characteristic measuring device (manufactured by Kyodo Electronics: SS-60).
As the head, an inductive head having a head gap of 0.17 μm and a track width of 4.0 μm was used.
The reproduced signal was observed, and the reproduced signal was read by a digital oscilloscope (LC334AM manufactured by LeCroy), and evaluated by the half-value width (PW50) of the signal. PW50 is 300
If it was less than 300 nm, it was good, and if it was 300 nm or more, it was poor.

The information signal pattern on the slave medium obtained by magnetic transfer using the magnetic transfer master carrier of the present invention has a small Ra-S value indicating the uniformity of the boundary of the pattern, and has a low signal distortion. It is shown to be small.

[0035]

Table 1 Boundary roughness Signal quality Ra-M (nm) Ra-S (nm) Signal distortion (nm) Example 1 10.89 8.66 270 nm Example 2 16.05 14.68 281 nm Comparative example 1 22.14 19.81 317 nm Comparative Example 2 30.54 30.01 362 nm

[0036]

According to the present invention, a magnetic transfer pattern formed in a convex shape on a magnetic transfer master carrier and having a roughness at a boundary between a convex portion and a concave portion of a predetermined size or less is used. Then, the magnetic recording signal transferred to the slave medium has high signal quality and small signal distortion, so that high-quality magnetic transfer can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a magnetic transfer master carrier used in the magnetic transfer method of the present invention.

FIG. 2 is a diagram illustrating a pattern formed on a magnetic transfer master carrier.

FIG. 3 is a diagram illustrating a method of forming a pattern by laser irradiation.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Master carrier for magnetic transfer, 2 ... Servo area, 3 ... Data area, 4 ... Slave medium, 5 ... Transfer pattern, 6
... Base, 7 ... Convex pattern, 8 ... Magnetic layer, 9 ... Track direction, 10 ... Concave part, 11 ... Boundary part, 12 ... Transfer information pattern, 13 ... Boundary part, 14 ... Radial direction, 15 ... Laser light, 16 … The end of the pattern

Claims (1)

[Claims] 1. A magnetic transfer master carrier used for magnetic transfer in which a magnetic transfer master carrier is brought into close contact with a slave medium and a transfer magnetic field is applied, wherein a convex portion corresponding to a transfer information signal is formed on a surface, and a concave portion is provided. The roughness of the portion in contact with the slave medium at the boundary between the
A magnetic transfer master carrier having a thickness of 0 nm or less.