WO2008053547A1

WO2008053547A1 - Pattern transferring stamper, method for manufacturing magnetic recording medium using the pattern transferring stamper, and the magnetic recording medium

Info

Publication number: WO2008053547A1
Application number: PCT/JP2006/321850
Authority: WO
Inventors: Takahiro Umada; Mineo Moribe; Yasuo Hosoda; Kazunobu Hashimoto; Masahiro Katsumura
Original assignee: Fujitsu Limited; Pioneer Corporation
Priority date: 2006-11-01
Filing date: 2006-11-01
Publication date: 2008-05-08

Abstract

A pattern transferring stamper (1) is provided for transferring a prescribed uneven pattern onto a deformable surface of a member to be a base for manufacturing a disc-like magnetic recording medium (D). The disc-like magnetic recording medium is provided with a data area (81) and a servo area (82) adjacent to the data area (81) in the circumference direction. The pattern transferring stamper (1) is provided with a guard band pattern section (11) that corresponds to the data area (81) of the disc-like magnetic recording medium (D), and a servo pattern section (12) that corresponds to the servo area (82) of the disc-like magnetic recording medium (D). At a portion where the guard band pattern section (11) and the servo pattern section (12) are adjacent to or close to each other, a recessed section (13) extending in the diameter direction is formed.

Description

No. TURN TRANSFER STAMPER, MAGNETIC RECORDING MEDIUM USING THE SAME, AND MAGNETIC RECORDING MEDIUM

Technical field

TECHNICAL FIELD [0001] The present invention relates to a pattern transfer stamper for transferring a fine uneven pattern onto a magnetic disk in the manufacture of a magnetic recording medium (for example, a magnetic disk). The present invention also relates to a method for manufacturing a magnetic recording medium using a pattern transfer stamper and the magnetic recording medium.

Background art

For example, as shown in FIG. 9, a magnetic disk has a data area 81 and a servo area 82 on the surface thereof. In the data area 81, a plurality of concentric tracks are provided. In the data area 81, a plurality of guard bands (not shown) are provided along the circumferential direction of the magnetic disk D in order to separate a plurality of tracks. The servo area 82 is provided adjacent to the data area 81 in the circumferential direction, and is used for detecting each track. In the servo area 82, a servo pattern (not shown) representing servo information indicating the position information of each track is provided.

By the way, for the production of a high-density magnetic disk D, a transfer method called a nanoimprint method has been proposed as shown in Patent Document 1, for example. In the nanoimprint method, a pattern transfer stamper (hereinafter simply referred to as a “stamper”) is pressed against the resin layer formed on the base substrate, thereby forming an uneven pattern on the surface of the resin layer. This is a technique for transferring. The stamper has a fine uneven surface at a pitch of nanometers. The uneven pattern represents a track, a servo pattern, or the like.

Patent Document 1: Japanese Patent Laid-Open No. 2005-286222 When manufacturing the magnetic disk D using the above-described Nino Impunt method, it is necessary to form a fine uneven pattern on the resin layer. A pressing technique is required. However, depending on the shape of the contact surface of the stamper with the resin layer, for example, insufficient filling of the resin may occur when the resin layer is pressed. For this reason, it is difficult to transfer an accurate and good uneven pattern. There is something wrong.

Disclosure of the invention

[0004] The present invention has been conceived under the circumstances described above. Accordingly, an object of the present invention is to provide a pattern transfer stamper capable of transferring a concave / convex pattern with good accuracy. Another object of the present invention is to provide a method for manufacturing a magnetic recording medium using the pattern transfer stamper. Another object of the present invention is to provide a magnetic recording medium manufactured using the above manufacturing method.

[0005] A pattern transfer stamper provided by the first aspect of the present invention is a base for manufacturing a disk-shaped magnetic recording medium having a data area and a servo area circumferentially adjacent to the data area. A pattern transfer stamper for transferring a predetermined concavo-convex pattern to a deformable surface of a member to be a data area corresponding concavo-convex pattern portion corresponding to the data area of the disk-shaped magnetic recording medium; A servo area corresponding uneven pattern portion corresponding to the servo area of the disk-shaped magnetic recording medium, and the data area corresponding uneven pattern portion and the servo area corresponding uneven pattern portion are adjacent or close to each other. A concave portion extending in the radial direction is formed in the portion.

[0006] Preferably, the pattern transfer stamper according to the present invention is disposed at a position where the concave portion extending along the radial direction communicates with or sufficiently close to the concave portion formed in the concave / convex pattern portion corresponding to the data area.

[0007] According to a second aspect of the present invention, a method of manufacturing a magnetic recording medium is provided. In this manufacturing method, a magnetic layer is formed on a substrate serving as a base of the disk-shaped magnetic recording medium, a resin layer is formed on the surface of the magnetic layer, and the present invention is applied to the resin layer. By pressing the concave / convex surface of the pattern transfer stamper provided by the first side surface, the concave / convex pattern of the pattern transfer stamper is transferred to the resin layer, and the surface of the magnetic layer is Using the oil layer as a mask, the exposed magnetic layer is etched to form a concavo-convex pattern.

[0008] According to a third aspect of the present invention, a method of manufacturing a magnetic recording medium is provided. This manufacture According to the method, the deformable substrate is pressed onto the deformable substrate by pressing the uneven surface of the stamper for noturn transfer provided by the first aspect of the present invention against the deformable substrate serving as a base of the disk-shaped magnetic recording medium. A pattern with or without a magnetic material is formed by transferring the concavo-convex pattern of the pattern transfer stamper and forming a magnetic layer in the concave portion of the concavo-convex pattern.

[0009] A magnetic recording medium provided by the fourth aspect of the present invention is manufactured using the method for manufacturing a magnetic recording medium provided by the second or third aspect of the present invention. .

Brief Description of Drawings

FIG. 1 is a perspective view of a main part showing an example of a pattern transfer stamper according to the present invention.

FIG. 2 is a diagram showing the surface of a magnetic disk.

FIG. 3 is a diagram showing a surface shape of a magnetic disk after being pressed by a pattern transfer stamper.

FIG. 4 is a diagram showing a configuration of a pattern transfer apparatus.

FIG. 5 is an explanatory diagram for explaining a method of manufacturing a magnetic disk.

FIG. 6 is an explanatory diagram for explaining a method of manufacturing a magnetic disk.

FIG. 7 is an explanatory diagram for explaining another method of manufacturing a magnetic disk.

FIG. 8 is an explanatory diagram for explaining another method of manufacturing a magnetic disk.

FIG. 9 is an external view of a magnetic disk.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a perspective view of a main part showing an example of a pattern transfer stamper according to the present invention. This pattern transfer stamper 1 (hereinafter simply referred to as “stamper 1”) is used, for example, when a magnetic disk D as a magnetic recording medium called a discrete track medium is manufactured. The stamper 1 is for transferring a fine uneven pattern onto the magnetic disk D by a so-called nanoimprint method.

[0013] As shown in FIG. 9 described in the background art section, the magnetic disk D is formed in a disk shape. The magnetic disk D has a data area 81 and a servo area 82 on one side. . In the data area 81, a plurality of concentric tracks (not shown) are formed. The servo area 82 is provided adjacent to the data area 81 in the circumferential direction, and is used for detecting each track.

FIG. 2 is a perspective view showing a data area 81 and a servo area 82 of the magnetic disk D. Referring to the figure, the data area 81 is provided with a plurality of tracks 3 (see the hatched portion along the circumferential direction) and a plurality of guard bands 2. The guard band 2 separates the plurality of tracks 3. The servo area 82 is provided with a servo pattern in which servo information such as track 3 position information is stored. As will be described later, the track 3 and a part of the servo pattern (see the shaded area) are made of, for example, a magnetic material. The portions other than the guard band 2 and the hatched portion of the servo pattern are formed of, for example, a nonmagnetic material.

The track 3 and the servo pattern are produced based on the concavo-convex pattern transferred by the stamper 1. That is, when the magnetic disk D is manufactured, the stamper 1 is brought into close contact with the base member (for example, a resin layer) of the magnetic disk D and pressed. As a result, a fine uneven pattern corresponding to the track 3 and the servo pattern is transferred and formed. Therefore, the stamper 1 has an uneven surface 10 (see FIG. 1) corresponding to the uneven pattern corresponding to the track 3 and the servo pattern.

The stamper 1 is a Ni substrate or a SiO substrate. The stamper 1 has an uneven surface 10

2

It has almost the same size as the surface of Ki disk D. The stamper 1 is manufactured by applying a resist, exposing with an electron beam, developing, and a plating process or etching on one surface of a separately prepared master.

The uneven surface 10 of the stamper 1 includes a guard band pattern portion 11 and a servo pattern portion 12 as shown in FIG. The guard band pattern portion 11 corresponds to the data area 81 of the magnetic disk D and has an uneven pattern in the radial direction. The servo pattern portion 12 corresponds to the servo area 82 of the magnetic recording medium D and has an uneven pattern in the circumferential direction. Concavities and convexities The concavity and convexity of the surface 10 have a pitch P of, for example, about lOOnm and a depth H of about 50 nm.

More specifically, the guard band pattern portion 11 has a plurality of convex portions 11a extending in the circumferential direction. It is made. The servo pattern portion 12 is formed with a plurality of convex portions 12a extending in the radial direction. In the stamper 1, a concave portion 13 extending in the radial direction is formed in a portion where the guard band pattern portion 11 and the servo pattern portion 12 are adjacent or close to each other, that is, in the vicinity of the right end portion of the servo pattern portion 12. The recess 13 is arranged at a position communicating or sufficiently close to the plurality of recesses 14 formed along the circumferential direction of the guard band pattern portion 11.

In the vicinity of the left end portion of the servo pattern portion 12, a recess 15 extending in the radial direction is formed adjacent to or in the vicinity of the guard band pattern portion 11.

FIG. 3 is a perspective view of the main part showing the surface shape of the base substrate of the magnetic disk D after being pressed by the stamper 1. As shown in FIG. 3, the base material of the magnetic disk D is composed of, for example, a glass substrate 31, a magnetic film 32, and a resin layer 33. The magnetic film 32 is formed on the glass substrate 32. The resin layer 33 is formed on the magnetic film 32.

As described above, a fine concavo-convex pattern corresponding to the concavo-convex surface 10 is formed by the stamper 1 in the resin layer 33 as shown in FIG. That is, when the resin layer 33 is pressed by the stamper 1, the resin in the convex part 12 a of the servo pattern part 12 flows into the concave part 18 of the servo pattern part 12. Further, the grease on the convex portion 12 a of the servo pattern portion 12 flows into the concave portion 13 between the servo pattern portion 12 and the guard band pattern portion 11. On the other hand, the grease in the convex portion 11 a of the guard band pattern portion 11 flows into the concave portion 14 of the guard band pattern portion 11. When the recess 13 and the recess 14 are communicated with each other, the grease in the protrusion 1 la of the guard band pattern portion 11 also flows into the recess 13.

Therefore, as shown in FIG. 3, the concave portion 13 and the concave portion 14 form the convex portion 16 and the convex portion 17 in the resin layer 33. When the recess 13 and the recess 14 are not in communication, the grease on the protrusion between the guard band pattern portion 11 and the recess 13 also flows into the recess 13 and the recess 14. If the area of the convex portion between the guard band pattern portion 11 and the concave portion 13 is large, the grease flowing into the concave portion 13 and the concave portion 14 becomes excessive, and good transfer of the concave / convex pattern is obstructed. Therefore, it is desirable that the recess 13 is disposed at a position sufficiently close to the recess 14 within a range that does not affect the transfer. Here, the convex portion 16 extends in the radial direction. The convex portion 17 is continuous or close to the side surface of the convex portion 16 and extends in the circumferential direction. in this case The convex portion 16 and the convex portion 17 are formed in an appropriate shape having, for example, a substantially rectangular parallelepiped shape.

In other words, in the present embodiment, the concave portion 13 and the concave portion 14 of the stamper 1 form the convex portion 16 and the convex portion 17 having an appropriate shape on the resin layer 33, and the concave / convex pattern is excellent and accurate. Can be transferred. As will be described later, the resin layer 33 is used as a mask for etching, but the etching process can be accurately performed by the convex portions 16 and 17, so that the track 3 and the servo pattern can be appropriately used. Can be formed.

[0024] The width and depth of the recess 13 are not particularly limited as long as the resin of the resin layer 33 can flow appropriately.

Next, a method for manufacturing the magnetic disk D using the stamper 1 will be described. In the production of the magnetic recording medium D, for example, a pattern transfer apparatus 20 as shown in FIG. 4 is used to transfer the concavo-convex pattern using the stamper 1 by the nanoimprint method.

The pattern transfer device 20 is installed inside the work chamber 21, for example. The pattern transfer device 20 includes a stamper 1, an upper fixing member 24, a lower panel 25, a lower lifting member 26, and a drive motor 27. The upper fixing member 24 holds the stamper 1 and the upper panel 22 horizontally and holds the upper unit 23. The lower panel 25 holds the upper fixing member 24 and the magnetic disk D horizontally. The lower elevating member 26 can move up and down while holding the lower panel 25. The drive motor 27 moves the lower lift member 26 up and down. The work chamber 21 is provided with a vacuum pump 28 for reducing the pressure in the work chamber 21. The vacuum pump 28 has a capability of reducing the pressure in the working chamber 21 to, for example, about lTorr.

[0027] The upper panel 22 is also made of, for example, quartz glass and plays a role of transmitting positioning light. A predetermined mechanism (for example, a light irradiator and a light detector) is provided inside the upper unit 23 (not shown). The predetermined mechanism is for positioning the stamper 1 with respect to the magnetic disk D in the horizontal plane. Therefore, it is preferable that the stamper 1 has a light-transmitting SiO substrate power.

2

[0028] The lower panel 25 includes a heater 29 that transfers heat to the stamper 1 and the magnetic disk D while being in contact with them. Inside the upper panel 25, a heater for transferring heat to the stamper 1 and the magnetic disk D may be provided. The lower panel 25 As the lower elevating member 26 is moved up and down by the slider 27, the lower elevating member 26 moves up and down integrally therewith. That is, the magnetic disk D held horizontally by the lower panel 25 is moved closer to or away from the stamper 1 held at a constant floor force. The stamper 1 and the magnetic recording medium D are pressed while being in close contact with the uneven surface 10 of the stamper 1.

FIG. 5 and FIG. 6 are diagrams showing the manufacturing process of the magnetic disk D. The stamper 1 and the magnetic disk D shown in FIGS. 5 and 6 have the concavo-convex pattern enlarged so that the concavo-convex pattern becomes clearer. Actually, a magnetic disk D of the size shown in Fig. 9 is installed.

[0030] First, in this manufacturing process, a base substrate of a magnetic disk D as shown in FIG. 5A is prepared. The base substrate is, for example, one in which a magnetic film 32 is formed on one surface of a glass substrate 31 and a resin layer 33 is formed on the surface of the magnetic film 32. The resin layer 33 is used as a mask in the manufacturing process (described later). The resin layer 33 is formed by spin coating or the like. The resin layer 33 is made of a thermoplastic resin such as polymethyl methacrylate resin (PMMA). The resin layer 33 has a glass transition point of around 100 ° C.

As shown in FIG. 5A, the uneven surface 10 of the stamper 1 is brought into close contact with the surface of the resin layer 33. When bringing the uneven surface 10 of the stamper 1 into close contact with the resin layer 33, the vacuum pump 28 (not shown in the figure) is operated. As a result, the work chamber 21 is brought into a vacuum state where the degree of vacuum achieved is about lTorr.

Next, the uneven surface 10 and the resin layer 33 of the stamper 1 are subjected to pressure treatment and heat treatment under vacuum. That is, as shown in FIG. 5B, the stamper 1 and the magnetic disk D are sandwiched between the upper panel 22 and the lower panel 25 in a state where the pressing surface 10 and the resin layer 33 are in contact with each other. The stamper 1 and the magnetic disk D are pressed by the upper panel 22 and the lower panel 25 with a pressing force F of about 2500 kgf, for example. The stamper 1 and the magnetic disk D are heated by the heater 29 to about 135 ° C., which is equal to or higher than the glass transition point of the resin layer 33.

[0033] After a required cooling period, the vacuum state of the working chamber 21 is released. Next, the uneven surface 10 of the stamper 1 is separated from the resin layer 33 as shown in FIG. 5C. That As a result, the resin layer 33 is in a state where the uneven pattern corresponding to the uneven surface 10 is transferred and cured. The uneven pattern of the resin layer 33 is used as an etching mask as will be described later.

As described above, the uneven pattern corresponding to the uneven surface 10 of the stamper 1 is transferred to the resin layer 33. In this case, a concave portion 13 is formed in a portion where the servo pattern portion 11 and the guard band pattern portion 12 of the stamper 1 are adjacent or close to each other. Therefore, the concavo-convex pattern formed on the resin layer 33 is a pattern having no transfer defect according to the concavo-convex surface 10. That is, a precise uneven pattern can be transferred to the resin layer 33.

[0035] Since the resin layer 33 immediately after the concavo-convex pattern is transferred has a residue portion unnecessary as a mask, the residue portion of the resin layer 33 is removed as shown in FIG. 5D. Thereby, the magnetic film 32 is exposed at the bottom of the concave portion of the resin layer 33.

The magnetic film 32 is etched using the resin layer 33 as a mask. Thereafter, the remaining resin layer 33 is removed, whereby a recess 34 is formed in the magnetic film 32 as shown in FIG. 6A.

Thereafter, as shown in FIG. 6B, the non-magnetic material 35 is fixed to the magnetic film 32 so as to cover the whole while filling the recess 34. Then, as shown in FIG. 6C, the surfaces of the magnetic film 32 and the nonmagnetic material 35 are polished. As a result, the magnetic film 32 is separated by the nonmagnetic material 35 embedded in the recess 34. Further, for example, a protective film and a lubricating film (both not shown) are formed on these surfaces, thereby completing the magnetic disk D as a discrete track medium.

7 and 8 are diagrams showing another manufacturing method of the magnetic disk D. FIG. The stamper 1 and the magnetic disk D shown in FIGS. 7 and 8 have the concavo-convex pattern enlarged so that the concavo-convex pattern becomes clearer. Actually, a magnetic disk D of the size shown in Fig. 9 is installed. This other manufacturing method is different from the manufacturing method described above in that a resin substrate 36 is used instead of the glass substrate 31. The other manufacturing method is the above-described manufacturing method in that the magnetic film 32 is formed after the pressing with the resin stamper 1 which does not form the magnetic film 32 on the surface of the glass substrate 31 in advance. And different.

[0039] First, in this manufacturing process, a deformable resin substrate can be used as a base material for the magnetic disk D. 36 is prepared. In another manufacturing method, as shown in FIG. 7A, after the working chamber 21 is evacuated, the uneven surface 10 of the stamper 1 is brought into direct contact with the surface of the resin substrate 36.

[0040] Next, the concavo-convex surface 10 of the resin substrate 36 is subjected to pressure treatment and heat treatment under vacuum. That is, the stamper 1 and the resin substrate 36 are sandwiched between the upper panel 22 and the lower panel 25 in a state where the uneven surface 10 and the resin substrate 36 are in contact with each other, as shown in FIG. 7B. The stamper 1 and the resin substrate 36 are pressed with a pressing force F. Thereafter, the stamper 1 and the resin substrate 36 are heated by the heater 29.

[0041] After a required cooling period, the vacuum state of the working chamber 21 is released. The uneven surface 10 of the stamper 1 is separated from the resin substrate 36 as shown in FIG. 7C. As a result, as shown in FIG. 7D, the resin substrate 36 is in a state where the uneven pattern corresponding to the uneven surface 10 is transferred and hardened.

Thereafter, as shown in FIG. 8A, a magnetic film 37 is fixed to the resin substrate 36 so as to cover the whole. 8B, the surface of the magnetic film 37 is polished, and the magnetic film 37 is separated from the resin substrate 36 on the surface of the base substrate. As a result, the magnetic disk D as the disc track medium is completed.

Note that the present invention is not limited to the above embodiments. For example, the object to which the concavo-convex pattern is transferred is not limited to the discrete track medium, and the stamper 1 according to the above embodiment can be applied if a desired fine concavo-convex pattern is required.

Claims

The scope of the claims

[1] A predetermined uneven pattern on a deformable surface of a base member for manufacturing a disk-shaped magnetic recording medium having a data area and a servo area adjacent to the data area in the circumferential direction. A pattern transfer stamper for transferring

Data area corresponding uneven pattern portion corresponding to the data area of the disk-shaped magnetic recording medium,

A servo area corresponding uneven pattern portion corresponding to the servo area of the disk-shaped magnetic recording medium,

A pattern transfer stamper, wherein a concave portion extending in the radial direction is formed in a portion where the concave / convex pattern portion corresponding to the data region and the concave / convex pattern portion corresponding to the servo region are adjacent to or close to each other.

[2] The recess extending along the radial direction is

The pattern transfer stamper according to claim 1, wherein the pattern transfer stamper is in communication with a recess formed in the uneven pattern portion corresponding to the data area.

[3] The magnetic material layer is formed on a substrate serving as a base of the disk-shaped magnetic recording medium, and a resin layer is formed on the surface of the magnetic material layer. The uneven pattern of the pattern transfer stamper is transferred to the resin layer by pressing the uneven surface of the pattern transfer stamper described above, and the resin layer on the surface of the magnetic layer is used as a mask. A method of manufacturing a magnetic recording medium, wherein an uneven pattern is formed by performing an etching process on the exposed magnetic layer.

[4] The pattern transfer substrate is applied to the deformable substrate by pressing the uneven surface of the pattern transfer stamper according to claim 1 against a deformable substrate serving as a base of the disk-shaped magnetic recording medium. A method for producing a magnetic recording medium, wherein a pattern of presence / absence of a magnetic material is formed by transferring a concave / convex pattern of a stamper and forming a magnetic layer in a concave portion of the concave / convex pattern.

[5] A magnetic recording medium produced using the method for producing a magnetic recording medium according to claim 3 or 4.