JP2005100605A - Process of producing master carrier for magnetic transfer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a master carrier for magnetic transfer which does not give rise to the breakage of magnetic layers by improving the adhesion force between a first ferromagnetic thin film and a third ferromagnetic thick film composed of Ni as a principal component. <P>SOLUTION: The process for producing the master carrier for magnetic transfer comprising manufacturing the master carrier by forming the first ferromagnetic thin film (F1) on the rugged pattern of a substrate having the rugged pattern meeting desired information on its surface, forming the third ferromagnetic thick film (F3) on the first ferromagnetic thin film (F1) by a vacuum film forming method and peeling the same from the substrate G1 having the rugged pattern is provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a magnetic transfer master carrier having an uneven pattern for magnetically transferring a desired magnetic pattern onto a slave medium in close contact with the slave medium.

In general, a magnetic recording medium that has a large capacity and is inexpensive to record a large amount of information as the amount of information increases, and more preferably a medium capable of high-speed access that can read out a necessary portion in a short time is desired. Yes. For example, high-density magnetic disk media used in hard disk devices and flexible disk (hereinafter referred to as FD) devices are known, and in order to realize such a large capacity, a magnetic head accurately scans a narrow track width. A so-called tracking servo technique for reproducing a signal with a high S / N ratio plays a major role.
Servo signals for tracking, address information signals, reproduction clock signals, etc. are recorded as so-called preformats at certain intervals in one round of the disk, and the magnetic head reads such preformat signals. It is set to be able to travel on the track accurately by correcting its own position.

  Currently, the preformat as described above is created by writing a signal for each disk and for each track using a dedicated servo recording device. The servo recording apparatus includes a magnetic head having a head width of about 75% of the track pitch, for example. First, the magnetic head is rotated at a half track pitch by rotating the disk while the magnetic head is close to the disk. The signal writing of each track is performed while moving.

  Since the servo recording apparatus as described above is expensive and it takes time to create a preformat, this process occupies a large part of the manufacturing cost, and the cost reduction is desired.

Therefore, a method has been proposed in which the preformat is not written for each track, but is realized by magnetic transfer (see, for example, Patent Documents 1 and 2).
JP 10-40544 A JP-A-10-269666

  For 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 as a magnetic transfer medium is prepared, and the master carrier and the slave medium are in close contact with each other. By applying a magnetic field for transfer, the magnetic pattern corresponding to the information (for example, servo signal) carried by the concave / convex pattern of the master carrier is transferred to the slave medium, and the relative positions of the master carrier and the slave medium are determined. Recording can be performed statically without change, accurate preformat recording is possible, and the time required for recording is extremely short.

  In order to improve the transfer quality in the magnetic transfer as described above, it is important how the master carrier can be held to the order of several thousand sheets with good adhesion without being damaged. In other words, if there is an inadequate contact, there will be areas where magnetic transfer will not occur, and if magnetic transfer does not occur, there will be a loss of signal in the magnetic information transferred to the slave medium and the signal quality will deteriorate, and the recorded signal will be a servo signal. In this case, the tracking function cannot be sufficiently obtained and the reliability is lowered.

FIG. 5 shows a manufacturing process of a master carrier for magnetic transfer according to a conventional method.
According to this, after forming a concavo-convex pattern according to information such as a servo signal on the surface thereof, a nickel (Ni) conductive layer is formed on a silicon substrate G1 ′ formed using a photoresist, and then nickel by electroplating or the like. A third ferromagnetic thick film F3 containing as a main component (6) is peeled off from the resist pattern substrate G1 ′, and a portion (at least part of the third ferromagnetic thick film F3 and the resist R1) ( a) and a part (b) of the silicon substrate G1 ′ are separated (7).
After the separation, if the resist R1 and the dust on the portion (a) on the third ferromagnetic thick film F3 side are cleaned and removed by O ₂ ashing or the like, the nickel original plate F3 is obtained (8). On this, the magnetic layer film F1 is provided by sputtering, and the magnetic transfer master carrier M is obtained.

As the substrate on which the resist pattern is formed, nickel, quartz plate, glass, aluminum, ceramics, synthetic resin, etc. are used in addition to the silicon. As the magnetic material of the magnetic layer film F1, Co, Co alloy (CoNi, CoNiZr, CoNbTaZr, etc.), Fe, Fe alloy (FeCo, FeCoNi, FeNiMo, FeAlSi, FeAl, FeTaN), Ni, Ni alloy (NiFe) Is used.
As the material of the third ferromagnetic thick film F3, Ni or Ni alloy or the like can be used. As the plating for producing this substrate, in addition to electroplating, electroless plating, sputtering, ion plating can be used. Including various metal film forming methods.

  As described above, in the conventional method, a Ni conductive layer is formed on the resist substrate G1 ′, and electroplating or the like is performed on the Ni conductive layer to form a patterned Ni substrate F3. A magnetic layer F1 is formed thereon by a sputtering method. The magnetic transfer master carrier M was formed and the magnetic transfer master carrier M thus obtained was used to perform magnetic transfer on a large number of slave media. It happened that the slave media was damaged.

The cause was thought to be due to the damage of the master, and as a result of analyzing the master, it was found that it was missing from the magnetic layer F1 formed on the patterned Ni substrate.
As a result of further investigation, it was found from the factor separation experiment conducted with the film thickness of the magnetic layer as a parameter that the internal stress inside the magnetic layer was larger than the adhesion between the substrate and the magnetic layer, and the peeling of the magnetic layer occurred there I found out that
This phenomenon was found to occur easily in the case of a fine pattern of 100 nm or less.

  A reduction in internal stress was attempted by changing the Ni substrate surface treatment for improving adhesion and the magnetic layer deposition conditions, and a certain effect could be confirmed, but a significant improvement was not achieved. From the above, it was concluded that improvement of the pattern film property is necessary after securing a certain level of adhesion between the magnetic layer and the Ni substrate.

  That is, when a soft magnetic layer made of FeCo is formed on the concavo-convex pattern of the concavo-convex pattern formed by Ni electroplating by a vacuum film formation method (for example, sputtering method), FeCo is deposited in the sputtering process. On the convex part, it is rare to deposit while maintaining the width of the convex part, and it spreads and accumulates in the lateral direction. Therefore, in a concavo-convex pattern finer than 100 nm, the deposited FeCo film contacts between adjacent convex portions, resulting in a disordered pattern shape. It is necessary to improve such pattern shape disturbance.

  The inventor first formed the ferromagnetic thin film (F1) prepared in the final step on the resist substrate, and electroplated using the ferromagnetic thin film as a conductive layer, so that the electrodynamic alloying process It was found that the pattern coverage by the formation of the ferromagnetic thin film (F1) can be improved by forming the ferromagnetic thin film (F1) on the resist pattern.

Specifically, as in the first aspect of the present invention, the first ferromagnetic thin film (F1) is formed on the surface of the substrate having a concavo-convex pattern according to desired information by a vacuum film forming method. And forming a third ferromagnetic thick film (F3) on the first ferromagnetic thin film (F1) and peeling it from the substrate having the concavo-convex pattern. It is.
The above-mentioned “substrate having a concavo-convex pattern according to desired information on the surface” includes the following.
(1) On a support having a smooth surface (for example, a glass plate, a silicon wafer, etc.), a concavo-convex pattern is formed using a photoresist (projections are made of photoresist),
(2) In the above (1), the convex photoresist is further etched as an etching resist, the support surface without the resist is etched, the photoresist constituting the convex part is removed, and the support surface itself is uneven. What is formed.
(3) A metal (for example, Ni) made by electroforming using the above (1) or (2) as a master and having an uneven surface.

  According to a second aspect of the present invention, in the method for manufacturing a magnetic transfer master carrier according to the first aspect, the third ferromagnetic thick film (F3) contains nickel (Ni).

  According to a third aspect of the present invention, in the method for manufacturing a magnetic transfer master carrier according to the first or second aspect, between the first ferromagnetic thin film (F1) and the third ferromagnetic thick film (F3). A second ferromagnetic thin film (F2) made of the same element as that of the third ferromagnetic thick film (F3) and formed by a vacuum film formation method is formed.

  According to a fourth aspect of the present invention, in the method for manufacturing a magnetic transfer master carrier according to the third aspect, the film thickness (dF2) of the second ferromagnetic thin film (F2) is in the range of 10 nm to 100 nm. Features.

  According to the fifth aspect of the present invention, in the method for manufacturing a magnetic transfer master carrier according to any one of the first to fourth aspects, the saturation magnetization (MsF1) of the first ferromagnetic thin film (F1) and the The saturation magnetization (MsF3) of the third ferromagnetic thick film (F3) has a relationship of (MsF1 / MsF3)> 1.

  According to the magnetic transfer medium of the present invention, the magnetic transfer master carrier manufactured by the method of manufacturing a magnetic transfer master carrier according to any one of claims 1 to 5 is used. Servo information is recorded.

  As described above, since the ferromagnetic thin film (F1) is formed first and electroforming is performed by using the ferromagnetic thin film as a conductive layer, the electrodynamic alloying process can be realized, so that the adhesion is greatly increased. In addition, by forming the ferromagnetic thin film (F1) on the resist pattern, the pattern coverage by forming the ferromagnetic thin film (F1) can be improved.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
First, a basic process of magnetic transfer for transferring information to a slave medium using a master carrier will be described with reference to FIGS.

FIG. 1 is a perspective view showing the slave medium 2 and the master carriers 3 and 4.
The slave medium 2 is, for example, a flexible disk in which a hub 2b is fixed to the center of a disk-shaped recording medium 2a. The recording medium 2a is a disk-shaped base 2c made of a nonmagnetic material such as a flexible polyester sheet. It has recording surfaces 2d and 2e having magnetic layers formed on both sides.

Further, the master carriers 3 and 4 are formed on a circular disk by a rigid body, and have a transfer information carrying surface formed with a fine uneven pattern closely attached to the recording surfaces 2d and 2e of the slave medium 2 on one surface thereof. It is. The master carriers 3 and 4 are provided with concave and convex patterns for the lower recording surface 2d and the upper recording surface 2e of the slave medium 2, respectively. Taking the master carrier 3 as an example, the concavo-convex pattern is formed in a donut-shaped region surrounded by a dotted line in the figure. The master carriers 3 and 4 shown in FIG. 1 are composed of substrates 31 and 41 on which a concavo-convex pattern is formed and soft magnetic layers 32 and 42 formed on the concavo-convex pattern. By providing a magnetic layer with good transfer characteristics in this way, better magnetic transfer can be performed.
When the substrate is a non-magnetic material, it is necessary to provide a magnetic layer.

  In addition, when a ferromagnetic metal substrate is used and the magnetic layer is coated on the uneven pattern surface, it is preferable to provide a nonmagnetic layer between the substrate and the magnetic layer in order to cut off the influence of the magnetism of the substrate. . Furthermore, if a protective film such as diamond-like carbon (DLC) is coated on the uppermost layer, this protective film improves the contact durability, and makes it possible to perform magnetic transfer more many times. Further, a Si film may be formed under the DLC protective film by sputtering or the like.

  2A and 2B are diagrams for explaining the basic steps of the magnetic transfer. FIG. 2A is a step in which a magnetic field is applied in one direction to initially DC magnetize the slave medium, and FIG. 2B is a master carrier and slave. (C) is a diagram showing the state after magnetic transfer, respectively, in the step of applying a magnetic field in the opposite direction while in close contact with the medium. In FIG. 2, only the lower recording surface 2d of the slave medium 2 is shown.

  As shown in FIG. 2A, initial magnetization (DC demagnetization) is applied to the slave medium 2 in advance by applying an initial magnetic field Hin in one direction in the track direction. Thereafter, as shown in FIG. 2 (b), the recording surface 2d of the slave medium 2 and the information carrying surface formed by coating the magnetic layer 32 on the fine uneven pattern of the substrate 31 of the master carrier 3 are brought into close contact with each other. Magnetic transfer is performed by applying a transfer magnetic field Hdu in the direction opposite to the initial magnetic field Hin in the track direction 2. As a result, as shown in FIG. 2C, information (for example, servo signals) corresponding to the uneven pattern of the information carrier surface of the master carrier 3 is magnetically transferred and recorded on the magnetic recording surface (track) of the slave medium 2. Is done. Here, the lower recording surface 2d and the lower master carrier 3 of the slave medium 2 have been described. However, the upper recording surface 2e of the slave medium 2 is also brought into close contact with the upper master carrier 4 as shown in FIG. Magnetic transfer is performed. Magnetic transfer to the upper and lower recording surfaces 2d and 2e of the slave medium 2 may be performed simultaneously or sequentially on each side.

  Even if the concave / convex pattern of the master carrier 3 is a negative pattern having a concave / convex shape opposite to the positive pattern of FIG. 2, the direction of the initial magnetic field Hin and the direction of the transfer magnetic field Hdu are reversed from the above. Similar information can be magnetically transferred and recorded. For the initial magnetic field and the transfer magnetic field, effective magnetic transfer can be performed by adopting values determined in consideration of the coercive force of the slave medium and the relative permeability of the master carrier and the slave medium.

FIG. 3 shows a method for manufacturing a magnetic transfer master carrier according to the first embodiment of the present invention. Hereinafter, a method for manufacturing a magnetic transfer master carrier will be described with reference to the drawings.
First, the surface of a silicon disk (or glass disk) G1 is polished smoothly (1), a resist adhesion liquid is applied thereon, and then a positive resist liquid is applied by spin coating or the like and baked. R1 is formed (2).

  A specific portion of the resist R1 is irradiated with laser beams (or electron beams) L1, L2,..., L5 modulated in response to servo signals (or their mirror symmetry signals), and the resist on the entire surface of the disk G1. A predetermined tracking pattern is exposed and drawn on R1 (3) (Note that hatching is omitted only in FIG. 3 to make it easy to see a specific portion of the resist R1, but originally there is hatching as in the other drawings. .) After the baking process is performed again, the resist R1 is developed, and the exposed portion is removed to form a concavo-convex shape with the resist as a convex part (4).

First, the first ferromagnetic thin film F1 is first formed on the substrate G1 having the concavo-convex shape by a vacuum film forming method such as sputtering (5). This process is a feature of the present invention. As the first ferromagnetic thin film F1, a FeCo alloy having good magnetic field absorbability is suitable.
Further, a third ferromagnetic thick film F3 is formed on the first ferromagnetic thin film F1 by electroplating or the like (6). The third ferromagnetic thick film F3 preferably contains nickel (Ni) as a main component, and Ni, Ni alloy, or the like can be used. The height of the unevenness is on the order of 100 nm, and the thickness of the third ferromagnetic thick film F3 is on the order of 300 μm.

As the resist pattern substrate G1 ′, nickel, silicon, quartz plate, glass, aluminum, ceramics, synthetic resin, or the like is used.
As the magnetic material for the magnetic layer film F1, Co, Co alloy (CoNi, CoNiZr, CoNbTaZr, etc.), Fe, Fe alloy (FeCo, FeCoNi, FeNiMo, FeAlSi, FeAl, FeTaN), Ni, Ni alloy (NiFe) are used. It is done.

Next, the third ferromagnetic thick film F3 and the first ferromagnetic thin film F1 are separated from the substrate G1 (7). At the time of the peeling, the convex resist formed on the substrate G1 is peeled off while adhering to the first ferromagnetic thin film F1 (see (a) of (7) in FIG. 3).
An easy peel layer may be provided between the G1 (R1) substrate / F1 in order to prevent physical destruction of the substrate at the time of peeling. The easily peelable layer is preferably composed of a chemically inert material. In particular, a carbon-based easy peeling layer (DLC, sputtering C) or the like is desirable.
The thickness of the easy release layer is preferably in the range of 2 to 10 nm, more preferably about 3 to 7 nm. In addition, when the thickness of an easily peelable layer is less than 2 nm, the role of an easily peelable layer is not played, and when thicker than 10 nm, the shape coverage of F1 layer will be reduced. Further, after peeling, this easy peeling layer may be used as a protective film.

After the separation, if the resist R1 in the portion (a) on the first ferromagnetic thin film F1 side is removed by O ₂ ashing or the like, a magnetic transfer master carrier M which is an inverted plate is completed. Looking at the obtained magnetic transfer master carrier M, the first ferromagnetic thin film F1 has no pattern irregularity (shoulder deformation) on the concave and convex portions of the third ferromagnetic thick film F3 (see arrow part B), and is almost the original master. It can be seen that a master carrier for magnetic transfer reflecting the shape is obtained (8).
By manufacturing in this way, the adhesion between the magnetic layer film F1 and the third ferromagnetic thick film F3 was improved, and the pattern coverage was improved.

  In the above manufacturing method, a substrate having a concavo-convex pattern corresponding to desired information (hereinafter referred to as “master”) having a concavo-convex pattern convex portion made of a resist is used, but the resist pattern is formed. The substrate G ′ to be etched, the resist is removed, and the surface of the silicon disk itself is formed with a concavo-convex pattern, or the metal formed by electroforming using the concavo-convex pattern surface created by any one of the above methods as a matrix It is also possible to make a metal having a concavo-convex pattern on its surface made of (for example, Ni) and use it as a master.

FIG. 4 shows a method for manufacturing a magnetic transfer master carrier according to the second embodiment of the present invention. Hereinafter, a method for manufacturing a magnetic transfer master carrier will be described with reference to the drawings.
In the manufacturing method according to the second embodiment, steps (1) to (5) up to manufacturing the substrate G1 with the unevenness are the same as those in FIG.
After forming the first ferromagnetic thin film F1 with FeCo alloy on the uneven substrate G1 by sputtering or vapor phase method (5), according to the second embodiment, the first ferromagnetic thin film F1 is formed. A second ferromagnetic thin film F2 made of the same element as that of the third ferromagnetic thick film F3 is formed thereon by sputtering (5 ′). The film thickness (dF2) of the second ferromagnetic thin film F2 is preferably in the range of 10 nm to 100 nm. Thereafter, a third ferromagnetic thick film F3 containing nickel (Ni) as a main component is formed on the second ferromagnetic thin film F2 by electroplating (6), and this is peeled off from the substrate G1 to form a third ferromagnetic film. The thick film F3 side portion (a) and the resist pattern substrate G1 portion (b) are separated (7). After the separation, if the resist R1 in the portion (a) on the third ferromagnetic thick film F3 side is removed by O ₂ ashing or the like, a magnetic transfer master carrier M which is an inverted plate is completed (8).

As described above, according to the second embodiment of the present invention, the same element as that of the third ferromagnetic thick film F3 is interposed between the first ferromagnetic thin film (FeCo) F1 and the third ferromagnetic thick film F3. The second ferromagnetic thin film F2 constituted by the above is formed by a sputtering method. This is because, if foreign matter (for example, FeCo) or the like is mixed in the plating bath, it may be reduced and precipitate impurities, so this fear can be eliminated by providing a thin layer of nickel Ni on FeCo in advance. It is to do.
When the obtained plate is viewed, the magnetic transfer in which the first ferromagnetic thin film F1 is formed in a right-angled state on the uneven portion of the third ferromagnetic thick film F3 without any pattern rounding (shoulder slippage) (see arrow part A). It can be seen that a master carrier is obtained (8).

The relationship between the saturation magnetization (MsF1) of the first ferromagnetic thin film (F1) and the saturation magnetization (MsF3) of the third ferromagnetic thick film (F3) is preferably the relationship of Equation 1.

(MsF1 / MsF3)> 1 (Formula 1)

The reason is that when signal recording is performed by magnetic transfer, the master carrier pattern portion must efficiently absorb and release a large amount of magnetic flux, and for this purpose, the master magnetic layer in the vicinity of the slave that contributes most to signal recording is required. This is because it is necessary to have unsaturation and high saturation magnetization at the time of magnetic transfer.
Therefore, with the relationship of the above formula 1, even if the third ferromagnetic thick film (F3) is saturated, the first ferromagnetic thin film (F1) is not yet saturated, and has high magnetic flux convergence and emission characteristics. Therefore, magnetic transfer having good signal quality can be realized.
Examples of the present invention will be described below.

A positive chemically sensitized electron beam resist of 100 nm is coated on an 8 吋 Si wafer, irradiated with an electron beam and developed to have a bit length of 0.15 μm in the radial region from the center of rotation to a position in the radial direction of 20 mm to 40 mm, A resist pattern is formed with radial lines having a track width of 1.0 μm, a track pitch of 1.1 μm, and a groove depth of 0.1 μm.
Thereafter, a soft magnetic layer: FeCo 25 at% layer was formed on the resist pattern at a thickness of 100 nm and a substrate temperature of 25 ° C.
The Ar sputtering pressure was 0.15 Pa (1.08 mTorr). The input power was 2.80 W / cm ² .
After forming FeCo 25 at% to 100 nm, Ni electroplating was performed until the thickness of the (Ni) substrate became 0.3 mm, and a master carrier that was isolated from the resist substrate after electroforming and cleaned was used.

In a vacuum film forming apparatus (Shibaura Mechatronics: S-50S sputtering apparatus), the pressure was reduced to 1.33 × 10 ⁻⁵ Pa (1.0 × 10 ⁻⁷ Torr) at room temperature, and then argon was introduced to 0.4 Pa. (3.0 mTorr), the glass plate was heated to 200 ° C., and a 3.5 inch type of CrTi 30 nm, CoCrPt 30 nm, Ms: 5.7 T (4500 Gauss), coercive force Hc: 199 kA / m (25000 e). A disc-shaped magnetic recording medium was produced and used as an in-plane slave medium.

1) Evaluation method of master durability:
Using the same master carrier, the contact pressure between slave carriers is set to 7.4 × 10 ⁻³ Pa (7.5 kgf / cm ² ), and after 10,000 contact / peeling cycles, the master surface is subjected to differential interference. 500 fields of view are observed randomly with a magnification of 480 times with a microscopic mirror. Within these 500 fields of view, there are precipitates and cracks in the magnetic layer.
(B) Good if less than 3 locations (○),
(B) If it was 3 or more places, it was evaluated as defective (x).

2) Electromagnetic conversion characteristics:
2-1) All slave media are installed in an electromagnetic conversion characteristic measuring apparatus (SS-60 manufactured by Kyodo Electronics) (head: reproducing head gap: 0.12 μm, reproducing track width: 0.45 μm, recording head gap: 0.18 μm) , Recording track width: GMR head of 0.51 μm), linear velocity at a radius of 40 mm is set to a linear velocity of 10 m / sec. The read signal was frequency-resolved with a spectroanalyzer, and the difference (C / N) between the peak intensity (C) of the primary signal and the externally pressed medium nozzle (N) was measured.
The relative C / N with reference to the C / N value of the head recording signal is
(I) If it is less than -3.0 dB, (○)
(B) Yes, if it is -3.0 to -4.0 dB (Δ),
(C) If it was -4.0 dB or more, it was judged as impossible (x).

2-2) In addition, the ratio (Wdup / Whead) between the transfer recording carrier peak line width (Wdup) and the head recording product (Whead) is
(I) Stable (○) if 1 or less,
(B) If it exceeded 1, it was judged as unstable (x).

In Example 1, an F1 layer having a thickness of 100 nm was formed of FeCo (Co 25%) before electroforming.
In Examples 2 to 5, the same magnetic transfer method as in Example 1 was performed except that the material and thickness of F1 were changed as shown in Table 1. That is, Example 2 is FeCo (Co25%) and a 200 nm thick F1 layer, Example 3 is FeCo (Co30%) and a 100 nm thick F1 layer, Example 4 is FeCo (Co30%) and a 500 nm thick F1 layer, In Example 5, a F1 layer of Ni having a thickness of 500 nm was used.

In Example 6, a master carrier for magnetic transfer similar to that in Example 1 was used except that a resist pattern substrate having a pattern formed on the substrate itself by RIE (depth: 100 nm) was used as a master.
In Example 7, a magnetic transfer master carrier similar to that in Example 1 was used except that a Ni substrate formed by plating on the resist pattern substrate was used.
Example 8 was the same master carrier for magnetic transfer as Example 6 except that a 1 nm DLC film was formed between the pattern substrate / F1.
Example 9 was the same master carrier for magnetic transfer as Example 6 except that a DLC film having a thickness of 5 nm was formed between the pattern substrate / F1.
Example 10 was the same master carrier for magnetic transfer as Example 6 except that a DLC film of 13 nm was formed between the pattern substrate / F1.

In Comparative Example 1, the same magnetic transfer method as in Example 1 was performed except that a magnetic layer was formed after formation on the patterned substrate after completion of Ni electroforming.
In Comparative Example 2, the same magnetic transfer method as in Example 2 was performed except that a magnetic layer was formed after formation on the patterned substrate after completion of Ni electroforming.
In Comparative Example 3, the same magnetic transfer method as in Example 4 was performed except that a magnetic layer was formed after formation on the patterned substrate after completion of Ni electroforming.

The results are shown in Table 1.

In Table 1, in Examples 1 to 4 and Examples 6 to 10, both adhesion and electromagnetic conversion characteristics (relative C / N, Wdup / Whead) are both ◯, and Example 5 is relative C / N of electromagnetic conversion characteristics. Except for △, both are ◯.
On the other hand, in Comparative Examples 1 to 3, both adhesion and Wdup / Whead) were x.

As a result, the first ferromagnetic thin film (F1) is first formed on the resist pattern substrate by sputtering, and the third ferromagnetic thick film (F3) is formed on the first ferromagnetic thin film (F1) by electroforming. It was confirmed that the method of the present invention is a very effective method.
In contrast, the conventional method of forming a Ni conductive layer on a resist substrate, performing electroforming, creating a patterned Ni substrate, and forming a magnetic layer thereon by sputtering is inferior. I was able to prove that.

FIG. 2 is a perspective view showing a slave medium 2 and master carriers 3 and 4. FIG. 2A is a diagram for explaining the basic process of magnetic transfer, FIG. 2A is a process in which a magnetic field is applied in one direction to initially DC magnetize a slave medium, and FIG. 2B is a diagram in which a master carrier and a slave medium are in close contact with each other. Then, the process of applying the opposite direction magnetic field, (c) is a diagram showing the state after the magnetic transfer. It is a manufacturing method of the magnetic transfer master carrier according to the first embodiment. It is a manufacturing method of the magnetic transfer master carrier according to the second embodiment. This is a method for manufacturing a magnetic transfer master carrier according to a conventional method.

Explanation of symbols

2 Slave mediums 3 and 4 Master carriers 31 and 41 Master substrates 32 and 42 on which uneven patterns are formed Soft magnetic layer F1 First ferromagnetic thin film F2 Second ferromagnetic thin film F3 Third ferromagnetic thick film G1 Silicon disk (or Glass disk)
L1, L2, ... Laser beam (or electron beam)
M1 Master transfer R1 resist for magnetic transfer

Claims (6)

  A first ferromagnetic thin film (F1) is formed on the concavo-convex pattern of a substrate having a concavo-convex pattern according to desired information on the surface by a vacuum film forming method, and a third ferromagnetic thin film (F1) is formed on the first ferromagnetic thin film (F1). A method of manufacturing a master carrier for magnetic transfer, comprising forming a ferromagnetic thick film (F3) and peeling it from the substrate having the concavo-convex pattern.   The method for manufacturing a master carrier for magnetic transfer according to claim 1, wherein the third ferromagnetic thick film (F3) contains nickel (Ni).   A second layer formed of the same element as the third ferromagnetic thick film (F3) between the first ferromagnetic thin film (F1) and the third ferromagnetic thick film (F3) and formed by a vacuum film forming method. 3. The method for producing a master carrier for magnetic transfer according to claim 1, wherein a ferromagnetic thin film (F2) is formed.   The method of manufacturing a magnetic transfer method according to claim 3, wherein the film thickness (dF2) of the second ferromagnetic thin film (F2) is in the range of 10 nm to 100 nm.   The saturation magnetization (MsF1) of the first ferromagnetic thin film (F1) and the saturation magnetization (MsF3) of the third ferromagnetic thick film (F3) have a relationship of (MsF1 / MsF3)> 1. Item 5. A method for producing a magnetic transfer master carrier according to any one of Items 1 to 4.   6. A magnetic transfer medium, wherein servo information is recorded by a magnetic transfer method using the magnetic transfer master carrier manufactured by the method for manufacturing a magnetic transfer master carrier according to claim 1.

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