JP2002216344A - Master support for magnetic duplication and method for using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the life of the master support for magnetic duplications to be made to increase, and the magnetic duplication to be performed to the large number of slave media. SOLUTION: The formation of the master support for magnetic duplications which is provided with the concavo-convex pattern whose depth d of a groove is 50 nm to 1000 nm, allows the master support to be used repeatedly, when the protrusion surface abrasion of the concavo-convex pattern is generated by using repeatedly the master support 3 and the scratch on the protrusion surface is produced due to a dust, etc., by polishing the protrusion surface, removing the damage portion 5, and varying the protrusion surface into a excellent state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a magnetic transfer master carrier having an uneven pattern for transferring information to a slave medium, and a method of using the same.

[0002]

2. Description of the Related Art In general, a magnetic recording medium is capable of so-called high-speed access, in which a large-capacity and inexpensive memory for recording a large amount of information with an increase in the amount of information, and more preferably a required portion can be read in a short time. A medium is desired. For example, high-density magnetic disk media used for hard disk devices and floppy (registered trademark) disk devices are known.
The magnetic head scans a narrow track width accurately and has a high S /
A so-called tracking servo technique for reproducing a signal at the N ratio plays a large role. In one round of the disk, tracking servo signals, address information signals, reproduced clock signals, and the like are recorded at certain intervals as a preformat.

[0003] The magnetic head is set so that it can run on the track accurately by reading such a preformat signal and correcting its own position. The current preformat is created by recording disks one by one or one track at a time using a dedicated servo recording device.

[0004] However, the servo recording device is expensive, and it takes time to create a preformat.
This process occupies a large part of the manufacturing cost, and it is desired to reduce the cost.

On the other hand, there has been proposed a method of realizing the preformat by magnetic transfer instead of writing the preformat one track at a time. For example, JP-A-63-183623,
JP-A-10-40544 and JP-A-10-26956
6 introduces a magnetic transfer technology. This magnetic transfer
A master carrier having a concavo-convex pattern corresponding to information to be transferred to a slave medium such as a magnetic disk medium which is a magnetic transfer medium is prepared, and a transfer magnetic field is applied while the master carrier and the slave medium are in close contact with each other. When applied, a magnetic pattern corresponding to information (for example, a servo signal) carried by the concavo-convex pattern of the master carrier is transferred to the slave medium. Recording can be performed efficiently, accurate preformat recording can be performed, and the time required for recording is extremely short.

[0006]

By the way, in the magnetic transfer method, in order to perform magnetic transfer by bringing the master carrier into close contact with the slave medium, it is necessary to first position the master carrier in close contact with the slave medium. . During this positioning, the master carrier and the slave medium rub against each other,
With the repeated magnetic transfer, the shape of the pattern surface carrying the information of the master carrier is worn, and the transfer accuracy is reduced. In addition, scratches due to dust or the like may occur on the master carrier surface, and such scratches also lower transfer accuracy.

If the transfer accuracy is reduced due to damage (including abrasion) on the pattern surface shape, it is necessary to replace the master carrier. However, this master carrier is very expensive.
How many slave media can be transferred with one master carrier is a very important issue in suppressing the manufacturing cost.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a long-life master carrier capable of performing magnetic transfer to more slave media.

[0009]

The first magnetic transfer master carrier of the present invention is a magnetic transfer master carrier provided with a concavo-convex pattern for transferring information to a slave medium. Pattern groove depth is 50nm
To 1000 nm, wherein the convex portion surface of the concave-convex pattern is polished at least once before use after production.

Further, the second magnetic transfer master carrier of the present invention is a magnetic transfer master carrier provided with a concavo-convex pattern for transferring information to a slave medium. Depth from 50nm to 100
0 nm, wherein the surface of the convex portion of the concave-convex pattern is polished at least once after use and reused.

In the above, "immediately after production" refers to a state in which a series of production steps have been completed, and the master carrier is in a state in which magnetic transfer is possible and is unused. Therefore, for example, in the normal master carrier manufacturing process, the polishing of the surface applied when there is a burr on the convex portion surface of the uneven pattern is polishing during the manufacturing process, and is different from the above-described polishing after manufacturing. It is.

The phrase "after production and before use" may be an unused state immediately after production, or may be used once and before reuse.

The first method of using a magnetic transfer master carrier according to the present invention is a method of using a magnetic transfer master carrier provided with a concavo-convex pattern for transferring information to a slave medium, the method comprising: The method is characterized in that the part surface is polished at least once after production and before use, and then used.

The second method of using a magnetic transfer master carrier according to the present invention is a method of using a magnetic transfer master carrier having a concavo-convex pattern for transferring information to a slave medium. Is characterized by being polished at least once after use and reused.

[0015] As a method of using each of the magnetic transfer master carriers, the surface of the convex portion of the concavo-convex pattern may be polished and used according to the degree of damage to the surface of the convex portion.

Here, "polishing in accordance with the degree of damage" may mean polishing every number of times or every number of days based on empirical values. The surface of the convex portion may be inspected and polished.

[0017]

According to the first magnetic transfer master carrier of the present invention, since the convex surface of the concave / convex pattern is used by being polished at least once before use after production, the convex / concave pattern of the concave / convex pattern is used. Even if the surface of the part is damaged, it is removed by polishing and used in a good surface condition.

In the second master carrier for magnetic transfer of the present invention, since the surface of the convex portion of the concave / convex pattern is polished at least once after use and reused, the abrasion of the surface shape due to use or the dust is reduced. Even when scratches are caused by, for example, the surface is reclaimed into a good surface state by polishing and used.

According to the first method of using the master carrier for magnetic transfer of the present invention, since the surface of the convex portion of the concave / convex pattern of the master carrier is polished at least once before manufacturing and before use, the concave / convex pattern is used. Even if the surface of the convex portion is damaged, it is used after being removed by polishing, so that good magnetic transfer is possible. In addition, this allows the master carrier to be used repeatedly, and as a result, the life of the master carrier is extended, and magnetic transfer to more slave media becomes possible. Therefore, the cost of magnetic transfer can be reduced, and a preformatted slave medium can be provided at a low price.

According to the second method for using the master carrier for magnetic transfer of the present invention, the surface of the projections of the concave / convex pattern of the master carrier is polished at least once after use and reused. Even when damage including damage due to abrasion of the shape and dust or the like is present on the surface of the convex portion of the uneven pattern, the damaged portion is removed and used after polishing, and good magnetic transfer is possible. In addition, this allows the master carrier to be used repeatedly, resulting in a longer life of the master carrier and magnetic transfer to more slave media. Therefore, the cost of magnetic transfer can be reduced, and a preformatted slave medium can be provided at a low price.

[0021]

Embodiments of the present invention will be described below in detail. FIGS. 1A and 1B are diagrams showing a magnetic transfer method using a master carrier according to the present invention, wherein FIG. 1A shows a step of applying a magnetic field in one direction to DC magnetize a slave medium, and FIG. FIG. 7C is a diagram illustrating a step of applying a magnetic field in the opposite direction by bringing the medium into close contact with the medium, and FIG. FIG. 2 is a sectional view showing another embodiment of the master carrier.

The outline of the magnetic transfer method is as follows. First, as shown in FIG.
, An initial static magnetic field Hin is applied in one direction in the track direction to perform DC magnetization (DC demagnetization) in advance. Thereafter, as shown in FIG. 1 (b), a soft magnetic layer 32 is formed on the magnetic transfer surface of the slave medium 2 and the fine uneven pattern on the substrate 31 of the master carrier 3 (the uneven shape is long in the radial direction, that is, in the track width direction). The slaved medium 2 is brought into close contact with the coated information carrying surface.
The magnetic transfer is performed by applying a transfer magnetic field Hdu in a direction opposite to the initial magnetic field Hin in the track direction. As a result, FIG.
As shown in (c), information corresponding to the information carrying surface unevenness pattern of the master carrier 3 is magnetically transferred and recorded on the magnetic transfer surface (track) of the slave medium 2.

Note that the master carrier 3 is capable of changing the direction of the initial magnetic field Hin and the direction of the transfer magnetic field Hdu even if the concave / convex pattern of the substrate 31 is a negative pattern having a concave / convex shape reverse to the positive pattern of FIG. By reversing the direction, similar information can be magnetically transferred and recorded.

When the substrate 31 is made of a ferromagnetic material such as Ni, magnetic transfer can be performed only with the substrate 31 and the soft magnetic layer 32 need not be covered. By providing 32, better magnetic transfer can be performed. When the substrate 31 is a non-magnetic material, it is necessary to provide the soft magnetic layer 32.

When the soft magnetic layer 32 is coated on the substrate 31 made of a ferromagnetic metal, the influence of the magnetism of the substrate 31 is cut off, as shown in FIG. It is more preferable to provide a non-magnetic layer 33 on the substrate. That is, in the master carrier 3 shown in FIG. 2, a nonmagnetic layer 33 is coated on a substrate 31 having the same concavo-convex pattern as described above, then a soft magnetic layer 32 is coated on the nonmagnetic layer 33, and further a top layer. A diamond-like carbon (DLC) protective film 34 is covered. By providing the DLC protective film 34 on the uppermost layer, contact durability is improved and magnetic transfer can be performed many times. Therefore, it is desirable to cover the uppermost layer also in the case of FIG. Note that a Si film may be formed below the DLC protective film 34 by sputtering or the like.

Next, a method of using the master carrier of the present invention will be described with reference to FIG. FIG. 3 (a) shows a master carrier immediately after production, FIG. 3 (b) shows a master carrier whose surface is damaged by repeated use, and FIG. 3 (c) shows that the surface of FIG. 3 (b) can be polished and reused. FIG. 3 is a partial cross-sectional view of each of the master carriers in a state.

As shown in FIG. 3A, the master carrier 3 is formed such that the depth d of the concave / convex pattern is about 50 nm to 1000 nm. Using this master carrier 3, magnetic transfer is performed as described with reference to FIG. While repeatedly performing magnetic transfer to a plurality of slave media, FIG.
As shown in (b), the surface of the convex portion of the concave / convex pattern of the master carrier 3 has friction during positioning with the slave medium,
Damage 5 occurs due to dust or the like adhering to the surface. When magnetic transfer is performed using a master carrier having a scratch on its surface and a convex portion with rounded corners, the transfer accuracy becomes extremely poor. Conventionally, in such a state, the master carrier is replaced with a new master carrier.

However, in the method of using the master carrier of the present invention, the master carrier 3 can be reused by polishing the damaged convex surface. FIG.
The surface of the projection shown in FIG. 2B is polished to the extent that the damaged portion 5 is removed (to the vicinity of the position shown by the dotted line in the figure).

A master carrier having a good convex surface without damage as shown in FIG. 3 (c) is reclaimed by polishing the surface of the convex portion and reused. Although the depth of the concavo-convex pattern is reduced by polishing, the pattern can be repeatedly used until the depth becomes about 5 nm to 10 nm. However, the minimum limit of the depth of the concavo-convex pattern depends on the width of the concavo-convex pattern in the track width direction and cannot be unconditionally specified.

As described above, the life of the master carrier is extended by polishing and reusing the surface of the convex portion of the concave / convex pattern, thereby enabling magnetic transfer to more slave media. The polishing of the surface of the convex portion of the concave / convex pattern may be performed periodically depending on the degree of damage obtained according to the number of times or the period of use of the master carrier, which is obtained empirically, or the state of the surface of the convex portion may be periodically determined. The inspection may be performed as necessary, and the inspection may be performed as necessary based on the result.

In the case of a master carrier having a magnetic layer, a protective layer, and the like as the upper layer, the upper layer needs to be coated again because the upper layer is removed by polishing. However,
The cost and labor can be reduced as compared with the case where a master carrier is manufactured from a substrate.

The method of using the above-mentioned master carrier is as follows.
Reproduction and reuse in the event of damage caused by use after production, but in the unused state after the production of the master carrier, the projections of the concavo-convex pattern in the production process or depending on the storage state The surface may be damaged, thereby reducing the transfer accuracy. According to another method of using the master carrier of the present invention, the surface is polished before production and used before use, that is, the surface is used in an unused state after production, as described above. Even if there is damage, it can be used after being removed by polishing, so that good magnetic transfer is possible. By repeating this polishing and use, magnetic transfer to more slave media is possible. .

Hereinafter, the production of the master carrier will be described in more detail. Nickel, silicon, quartz plate, glass, aluminum, alloy,
Use ceramics, synthetic resin, etc. The formation of the concavo-convex pattern is performed by a stamper method, a photofabrication method, or the like. Here, the production of the master carrier in the case where the stamper method is used for forming the concavo-convex pattern will be described.

First, a photoresist is formed on a glass plate (or quartz plate) having a smooth surface by spin coating or the like by a stamper method, and a laser beam modulated according to a servo signal while rotating the glass plate. (Or an electron beam) to expose a predetermined pattern on the entire surface of the photoresist, for example, a pattern corresponding to a servo signal extending linearly in a radial direction from the center of rotation to each track to a portion corresponding to each frame on the circumference. After that, the photoresist is developed to remove the exposed portions, thereby obtaining a master having an uneven shape due to the photoresist. Next, based on the uneven pattern on the surface of the master, this surface is plated (electroformed),
A Ni substrate having a positive concavo-convex pattern is prepared and peeled from the master. This substrate is used as a master carrier as it is, or a non-magnetic layer, a soft magnetic layer, and a protective film are coated on the concavo-convex pattern as needed to obtain a master carrier.

Further, a second master is prepared by plating the master, and plating is performed using the second master.
A substrate having a negative concavo-convex pattern may be produced. Further, a second master may be plated or pressed with a resin solution and cured to form a third master, and the third master may be plated to form a substrate having a positive concavo-convex pattern. .

After forming a pattern using a photoresist on the glass plate, etching is performed to form a hole in the glass plate, a master from which the photoresist is removed is obtained, and a substrate is formed in the same manner as described above. You may.

As the material of the substrate made of metal, Ni or a Ni alloy can be used. The plating for forming this substrate is performed by various kinds of metal film formation including electroless plating, electroforming, sputtering, and ion plating. Law is applicable. Depth of uneven pattern on substrate (height of protrusion)
Is preferably in the range of 80 nm to 800 nm, more preferably 150 nm to 600 nm. This concavo-convex pattern is formed long in the radial direction in the case of a servo signal.
For example, the length in the radial direction is preferably from 0.3 to 20 μm, and the length in the circumferential direction is preferably from 0.2 to 5 μm. It is preferable to select a pattern that is longer in the radial direction in this range as a pattern carrying servo signal information. .

When the substrate is a ferromagnetic material made of Ni or the like, magnetic transfer can be performed using only this substrate, but better magnetic transfer can be performed by providing a magnetic layer having good transfer characteristics. When the substrate is a non-magnetic material, it is necessary to provide a magnetic layer.

When a magnetic layer is coated on a substrate made of a ferromagnetic metal, it is preferable to provide a non-magnetic layer between the substrate and the magnetic layer in order to eliminate the influence of the magnetism of the substrate.

The magnetic layer (soft magnetic layer) is formed by depositing a magnetic material by vacuum deposition such as vacuum deposition, sputtering, or ion plating, or by plating.
As the magnetic material of the magnetic layer, Co, a Co alloy (CoN
i, CoNiZr, CoNbTaZr, etc.), Fe, Fe
Alloys (FeCo, FeCoNi, FeNiMo, FeA
lSi, FeAl, FeTaN), Ni, Ni alloy (N
iFe) can be used. Particularly preferably, FeC
o, FeCoNi. The thickness of the magnetic layer is from 50 nm to
A range of 500 nm is preferred, more preferably 150 nm.
nm to 400 nm. The material of the non-magnetic layer provided as an underlayer below the magnetic layer may be Cr, CrTi,
CoCr, CrTa, CrMo, NiAl, Ru, C,
Ti, Al, Mo, W, Ta, Nb or the like is used. The nonmagnetic layer can suppress deterioration of signal quality when the substrate is a ferromagnetic material.

It is preferable that a protective film such as DLC is further provided on the magnetic layer, and a lubricant layer may be provided.
More preferably, a DLC film of 5 to 30 nm and a lubricant layer are present as a protective film. Further, an adhesion strengthening layer such as Si may be provided between the magnetic layer and the protective film.

A resin substrate may be prepared using the master and a magnetic layer may be provided on the surface of the resin substrate to form a master carrier. As a resin material for the resin substrate, an acrylic resin such as polycarbonate / polymethyl methacrylate, a vinyl chloride resin such as polyvinyl chloride / vinyl chloride copolymer, an epoxy resin, an amorphous polyolefin, and a polyester can be used. Polycarbonate is preferred in terms of moisture resistance, dimensional stability, cost, and the like. If there are burrs on the molded product, they are removed by varnish or polish. The height of the pattern protrusion of the resin substrate is 50 to 10
It is preferably in the range of 00 nm, more preferably 200 to
The range is 500 nm.

A master layer is obtained by coating a magnetic layer on the fine pattern on the surface of the resin substrate. In addition, the magnetic layer
A magnetic material is formed into a film by a vacuum film forming method such as a vacuum evaporation method, a sputtering method, or an ion plating method, or a plating method.

[Brief description of the drawings]

FIG. 1 is a diagram showing a magnetic transfer method using a master carrier according to one embodiment of the present invention.

FIG. 2 is a sectional view showing an embodiment of another master carrier.

FIG. 3 shows a method for using a master carrier according to one embodiment of the present invention.

[Explanation of symbols]

 2 Slave medium 3 Master carrier 5 Damaged part 31 Substrate 32 Soft magnetic layer 33 Nonmagnetic layer 34 Protective film

Claims (5)

[Claims] 1. A master carrier for magnetic transfer provided with a concavo-convex pattern for transferring information to a slave medium, wherein a depth of a groove of the concavo-convex pattern immediately after manufacture is 50 nm to 1000 nm; The convex surface is
A master carrier for magnetic transfer characterized in that it is polished at least once before use after production. 2. A magnetic transfer master carrier provided with a concave / convex pattern for transferring information to a slave medium, wherein the concave / convex pattern immediately after manufacture has a groove depth of 50 nm to 1000 nm, The convex surface is
A master carrier for magnetic transfer, which is polished at least once after use and reused. 3. A method of using a magnetic transfer master carrier provided with a concavo-convex pattern for transferring information to a slave medium, wherein the convex surface of the concavo-convex pattern is polished at least once after production and before use. A method for using a magnetic transfer master carrier, which is used afterwards. 4. A method of using a magnetic transfer master carrier having a concavo-convex pattern for transferring information to a slave medium, wherein the convex surface of the concavo-convex pattern is polished at least once after use and reused. A method of using a master carrier for magnetic transfer, which comprises: 5. The method for using a master carrier for magnetic transfer according to claim 3, wherein the surface of the convex portion of the concave-convex pattern is polished and used according to the degree of damage to the surface of the convex portion. .