WO2010089850A1

WO2010089850A1 - Magnetic storage medium, method of manufacturing magnetic storage medium, information storage device, and apparatus for manufacturing magnetic storage medium

Info

Publication number: WO2010089850A1
Application number: PCT/JP2009/051806
Authority: WO
Inventors: 弘人竹下
Original assignee: 富士通株式会社
Priority date: 2009-02-03
Filing date: 2009-02-03
Publication date: 2010-08-12

Abstract

In a magnetic storage device in which the width in a medium in-plane direction of a servo pattern in a servo region is larger than the width of a medium in-plane direction of dots in a data region, the magnetization in a vertical direction in the servo pattern is maintained to be stable. The concentration of a non-magnetic element at the grain boundaries of the magnetic films forming the servo pattern is higher than the concentration of a non-magnetic element in the grains of the magnetic film. Such a magnetic storage medium can be provided by a method of manufacturing the magnetic storage medium including a non-magnetic film arranging step of arranging the non-magnetic film only on the magnetic films forming the servo pattern out of the magnetic films forming the servo pattern and the magnetic films forming dots, and a segregation step of segregating the non-magnetic element at the grain boundaries of the magnetic films forming the servo pattern by heating the non-magnetic films arranged by the non-magnetic film arranging step.

Description

Magnetic storage medium, method for manufacturing magnetic storage medium, information storage apparatus, and apparatus for manufacturing magnetic storage medium

The present invention relates to a magnetic storage medium for recording data by a perpendicular magnetic recording method, a method for manufacturing the magnetic storage medium, an information storage apparatus having the magnetic storage medium, and a magnetic storage medium manufacturing apparatus for manufacturing the magnetic storage medium. .

With the recent increase in recording density of magnetic storage media, a perpendicular magnetic recording method for recording data by magnetizing a magnetic film in the perpendicular direction of the medium has become the mainstream technology. And bit patterned media for realizing further higher recording density has attracted attention (see Patent Document 1).

This bit patterned media has data areas and servo areas alternately, and the data area has high density of magnetic film dots isolated by non-magnetic material to achieve high recording density. Yes. In addition, the bit patterned media generally has a magnetic film pattern in the servo area that is wider in the disk in-plane direction than the data area dots, and in particular, has a magnetic film pattern extending in the radial direction. There are many cases.

JP-A-3-22211

As described above, the servo pattern of bit patterned media has a magnetic film pattern that is wider in the medium in-plane direction than the data area dots, so that the shape magnetism tends to be more easily oriented in the medium in-plane direction than in the vertical direction. Anisotropy is produced. Therefore, the conventional bit patterned media has a problem that the coercive force to keep the magnetization in the servo pattern stable in the vertical direction is weak.

Accordingly, the disclosed technique has been made to solve the above-described problems of the prior art, and a magnetic storage medium capable of stably maintaining the magnetization in the servo pattern in the vertical direction, and a method for manufacturing the magnetic storage medium An object of the present invention is to provide an information storage device having the magnetic storage medium and a magnetic storage medium manufacturing apparatus for manufacturing the magnetic storage medium.

In order to solve the above-described problems and achieve the object, the disclosed magnetic storage medium is formed such that the width of the servo pattern in the servo area in the servo area is wider than the width of the dot in the data area in the data area. In addition, it is a requirement that the concentration of the nonmagnetic element in the crystal grain boundary of the magnetic film forming the servo pattern is higher than the concentration of the nonmagnetic element in the crystal grain of the magnetic film.

The disclosed magnetic storage medium can stably maintain the magnetization in the vertical direction in the servo pattern.

FIG. 1 is a diagram for explaining a method of manufacturing a magnetic storage medium. FIG. 2 is a diagram for explaining a magnetic storage medium. FIG. 3 is a diagram for explaining a magnetic storage medium. FIG. 4 is a diagram for explaining a magnetic storage medium. FIG. 5 is a diagram showing the configuration of the information storage device. FIG. 6 is a diagram showing the configuration of the magnetic storage medium manufacturing apparatus. FIG. 7 is a flowchart showing the flow of processing by the magnetic storage medium manufacturing apparatus. FIG. 8 is a diagram for explaining the method of manufacturing the magnetic storage medium according to the second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic storage medium 2 Magnetic film 3 Nonmagnetic film 4 Resist 20 Data area 21 Dot 30 Servo area 31 Servo pattern 40 Nonmagnetic material 50 Information storage device 52 Recording head 53 Voice coil motor (VCM)
54 Read channel (RDC)
55 Hard Disk Controller (HDC)
DESCRIPTION OF SYMBOLS 56 Power amplifier 57 Preamplifier 60 Magnetic storage medium manufacturing apparatus 61 Substrate installation part 62 Resist pattern formation part 63 Ion etching part 64 Resist removal part 65 Heating part 66 Filling / flattening part

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a magnetic storage medium, a magnetic storage medium manufacturing method, an information storage device, and a magnetic storage medium manufacturing device will be described in detail below with reference to the accompanying drawings.

[Method of manufacturing magnetic storage medium]
(A) Resist Pattern Formation Step FIG. 1 is a diagram for explaining a method for manufacturing a magnetic storage medium. As shown in FIG. 1A, a recording film (magnetic film) 2 of a magnetic material (for example, cobalt and platinum) is formed on a substrate, and a nonmagnetic element (for example, chromium, copper) is formed on the magnetic film 2. , Gold, silver, etc.) is formed. The magnetic film 2 may be an alloy containing cobalt or platinum as a main component. Further, the nonmagnetic film 3 may be an alloy mainly composed of chromium, copper, gold, silver or the like.

Subsequently, a resist pattern corresponding to the servo pattern 31 and the dot 21 is formed on the nonmagnetic film 3. Specifically, the resist 4 is laminated so that the resist pattern of the servo pattern 31 is thicker than the resist pattern of the dots 21 to form a resist pattern. For example, a film of a resist 4 is formed on the nonmagnetic film 3 with a uniform thickness, and a portion that becomes the nonmagnetic body 40 is irradiated with an electron beam or light having a higher dose than a portion that becomes the dot 21, The resist pattern is formed by irradiating the electron beam or light having a higher dose than the portion to be the servo pattern 31 to the portion to be the dot 21.

(B) Ion Etching Step Next, as shown in FIG. 1B, among the magnetic film 2 forming the servo pattern 31 in the servo area 30 and the magnetic film 2 forming the dot 21 in the data area 20, the servo The nonmagnetic film 3 is disposed only on the magnetic film 2 forming the pattern 31. For example, ion etching is performed until the nonmagnetic film 3 remains only on the magnetic film 2 forming the servo pattern 31. At this time, the dot 21 and the nonmagnetic film 3 at the location to become the nonmagnetic material 40 are removed from the substrate.

(C) Resist removal / heating process Subsequently, cleaning with an organic solvent and reactive ion etching (ashing) using a gas such as oxygen are performed to form a servo pattern 31 as shown in FIG. The resist 4 remaining on the magnetic film 2 is removed. Then, the medium is heated to segregate nonmagnetic elements at the crystal grain boundaries of the magnetic film 2 forming the servo pattern 31. At this time, since the crystal grains of the magnetic material constituting the magnetic film 2 are isolated by the nonmagnetic element, they are magnetically isolated.

(D) Filling / Planarizing Step Next, as shown in FIG. 1 (d), the groove formed by the ion etching step is filled with a nonmagnetic material, and a chemical mechanical polishing (CMP) method is performed. Etc. is used to flatten the surface. Finally, a protective film and a lubricant film are formed on the substrate. Thereby, the magnetic storage medium 1 in which the concentration of the nonmagnetic element in the crystal grain boundary of the magnetic film forming the servo pattern 31 is higher than the concentration of the nonmagnetic element in the crystal grain of the magnetic film can be manufactured.

[Magnetic storage medium]
2 to 4 are diagrams for explaining the magnetic storage medium. The magnetic storage medium 1 manufactured by the above manufacturing method has data areas 20 and servo areas 30 alternately as shown in FIG. 2 shows an example of the magnetic storage medium 1 having a phase servo pattern, it may be a magnetic storage medium having an area (or amplitude) servo pattern.

The data area 20 is an area where data is read and written by the recording head, and has dots 21 of the magnetic film 2 isolated by the nonmagnetic material 40 as shown in FIG. The dot 21 is an aggregate of crystal grains of one magnetic material or crystal grains that are magnetically strongly coupled. The servo area 30 is an area in which servo information for head positioning is written. As shown in FIG. 4, the servo pattern 31 is wider in the circumferential direction than the dot 21 and extends in the radial direction. Have.

In the servo pattern 31, the concentration of the nonmagnetic element in the crystal grain boundary of the magnetic film 2 is higher than the concentration of the nonmagnetic element in the crystal grain of the magnetic film 2. In other words, as shown in FIG. 4, in the servo pattern 31, nonmagnetic elements are segregated at the crystal grain boundaries of the magnetic film 2, and the crystal grains of the magnetic film 2 are magnetically isolated from each other. Thus, in the magnetic storage medium 1 according to the first embodiment, the magnetization in the servo pattern 31 is less likely to be directed in the circumferential direction and the radial direction, and the vertical magnetization in the servo pattern 31 is more stable than in the conventional magnetic storage medium. Can be kept in.

[Information storage device]
FIG. 5 is a diagram showing the configuration of the information storage device. As shown in FIG. 5, the information storage device 50 includes a magnetic storage medium 1, a recording head 52, a voice coil motor (VCM) 53, a read channel (RDC) 54, a hard disk controller (HDC) 55, a power amplifier 56, and a preamplifier 57. Have

The recording head 52 reads and writes data stored in the magnetic storage medium 1, and the preamplifier 57 amplifies the reproduction signal read from the magnetic storage medium 1 by the recording head 52 and outputs the amplified signal to the RDC 54. The RDC 54 extracts servo information and data from the reproduction signal and outputs them to the HDC 55.

HDC 55 is a controller that controls the operation of the entire information storage device 50, and outputs a signal for controlling the operation of the VCM 53 to the power amplifier 56 based on the servo information. The VCM 53 controls the position of the recording head 52 based on a signal received from the HDC 55 via the power amplifier 56.

[Magnetic storage medium manufacturing equipment]
FIG. 6 is a diagram showing the configuration of the magnetic storage medium manufacturing apparatus. As shown in FIG. The magnetic storage medium manufacturing apparatus 60 includes a substrate placement portion 61 for placing a substrate having a laminated structure up to the backing layer, a resist pattern formation portion 62, an ion etching portion 63, a resist removal portion 64, a heating portion 65, A filling / flattening portion 66 is provided.

The resist pattern forming unit 62 forms a magnetic film 2 of a magnetic material on a substrate, and forms a nonmagnetic film 3 of a nonmagnetic element on the magnetic film 2. Subsequently, the resist pattern forming unit 62 forms a resist pattern corresponding to the servo pattern 31 and the dots 21 on the nonmagnetic film 3. Specifically, the resist 4 is laminated so that the resist pattern of the servo pattern 31 is thicker than the resist pattern of the dots 21 to form a resist pattern.

The ion etching unit 63 is a nonmagnetic film only on the magnetic film 2 forming the servo pattern 31 among the magnetic film 2 forming the servo pattern 31 in the servo area 30 and the magnetic film 2 forming the dot 21 in the data area 20. 3 is arranged. Specifically, ion etching is performed by irradiating the substrate with ions until the nonmagnetic film 3 remains only on the magnetic film 2 forming the servo pattern 31. In addition, the ion etching part 63 is also called a nonmagnetic film | membrane arrangement | positioning part.

The resist removing unit 64 performs reactive ion etching to remove the resist 4 remaining on the magnetic film 2 forming the servo pattern 31. The heating unit 65 heats the substrate and segregates nonmagnetic elements at the crystal grain boundaries of the magnetic film 2 forming the servo pattern 31. The heating unit 65 is also referred to as a segregation unit.

The filling / planarizing unit 66 fills the groove formed by the ion etching unit 63 with a nonmagnetic material and planarizes the surface. Then, the filling / planarizing unit 66 forms a protective film and a lubricant film on the substrate.

[Processing by magnetic storage medium manufacturing equipment]
FIG. 7 is a flowchart showing the flow of processing by the magnetic storage medium manufacturing apparatus. As shown in FIG. 7, when it is detected that the substrate on which the laminated structure up to the backing layer is formed is installed on the substrate installation unit 61 (Yes in step S101), the resist pattern forming unit 62 detects the magnetic material on the substrate. A magnetic film 2 is formed, and a nonmagnetic film 3 of a nonmagnetic element is formed on the magnetic film 2 (step S102). Subsequently, the resist pattern forming unit 62 forms a resist pattern corresponding to the servo pattern 31 and the dots 21 on the nonmagnetic film 3 (step S103).

When the resist pattern is formed, the ion etching unit 63 performs ion etching until the nonmagnetic film 3 remains only on the magnetic film 2 forming the servo pattern 31 (see FIG. 4) (step S104). Subsequently, the resist removing unit 64 removes the remaining resist 4 (step S105), and the heating unit 65 heats the substrate (step S106).

When a nonmagnetic element segregates at the crystal grain boundary of the magnetic film 2 forming the servo pattern 31 (see FIG. 4), the filling / planarizing unit 66 fills the groove formed by the ion etching unit 63 with a nonmagnetic material. Then, the surface is flattened (step S107). Then, the filling / planarizing unit 66 forms a protective film and a lubricant film on the substrate (step S108), and ends the process.

[Effects of Example 1]
As described above, the magnetic storage medium according to the first embodiment can stably maintain the magnetization in the vertical direction in the servo pattern. In the magnetic storage medium according to the first embodiment, since the crystal grains in the servo pattern are magnetically isolated from each other, even if there are crystal grains whose magnetization is reversed in the servo pattern, the starting point is It is possible to prevent the reverse magnetic domain from expanding. Also in this respect, the magnetic storage medium according to the first embodiment can keep the magnetization of the servo pattern stable in the vertical direction.

Further, by using the magnetic storage medium manufacturing method and the magnetic storage medium manufacturing apparatus according to the first embodiment, it is possible to provide a magnetic storage medium capable of stably maintaining the perpendicular magnetization in the servo pattern. In addition, according to the method for manufacturing a magnetic storage medium according to the first embodiment, a medium in which dots and servo patterns are formed based on the same magnetic material can be manufactured. A magnetic storage medium that can keep the magnetization in the vertical direction stable can be manufactured.

Further, if the method for manufacturing a magnetic storage medium according to the first embodiment is used, it is not necessary to change the shape of the servo pattern, so that the conventional servo system can be used as it is.

Hereinafter, another embodiment will be described as a second embodiment.

FIG. 8 is a diagram for explaining the method of manufacturing the magnetic storage medium according to the second embodiment. As shown in FIG. 8A, a film is formed (coated) in the order of the magnetic film 2, the nonmagnetic film 3, the resist 4-1 having low exposure sensitivity, and the resist 4-2 having high exposure sensitivity. ) Then, as shown in FIG. 8B, the portion that becomes the nonmagnetic material 40 is irradiated with an electron beam or light having a higher dose than the portion that becomes the dot 21, and the servo pattern 31 is applied to the portion that becomes the dot 21. A resist pattern is drawn by irradiating an electron beam or light having a dose higher than that of the portion to be. In this way, the thickness of the resist 4 remaining on the substrate can be controlled with high accuracy.

Further, a resist pattern may be formed using a nanoimprint lithography method. That is, a master disk (imprint mold) in which a groove deeper than the portion corresponding to the dot 21 is formed at a position corresponding to the servo pattern 31 is formed, and the magnetic film 2, the nonmagnetic film 3, and the resist 4 are formed. The resist pattern is transferred by pressing the master against the filmed substrate. In this way, it is possible to easily form the resist 4 in which the resist pattern of the servo pattern 31 is thicker than the resist pattern of the dots 21.

Claims

The circumferential width of the servo pattern in the servo area is formed wider than the circumferential width of the dots in the data area, and the concentration of the nonmagnetic element in the crystal grain boundary of the magnetic film forming the servo pattern is A magnetic storage medium characterized by being higher in concentration than the nonmagnetic element in the crystal grains of the magnetic film.
A nonmagnetic film disposing step of disposing a nonmagnetic film only on the magnetic film forming the servo pattern among the magnetic film forming the servo pattern in the servo region and the magnetic film forming the dot in the data region;
A segregation step of segregating nonmagnetic elements to crystal grain boundaries of the magnetic film forming the servo pattern by heating the nonmagnetic film disposed in the nonmagnetic film disposing step;
A method for manufacturing a magnetic storage medium, comprising:
When a resist pattern corresponding to the servo pattern and dots is formed on the nonmagnetic film of the substrate in which a nonmagnetic film is laminated on the magnetic film, the resist of the servo pattern is more than the resist pattern of the dots. A resist pattern forming step for forming a thick pattern;
The nonmagnetic film forming step includes removing the nonmagnetic film on the magnetic film forming the dots and arranging the nonmagnetic film only on the magnetic film forming the servo pattern. The method of manufacturing a magnetic storage medium according to claim 2, wherein the resist pattern, the nonmagnetic film, and the magnetic film are etched.
In the resist pattern forming step, the servo region is formed on a substrate in which a nonmagnetic film, a first resist, and a second resist having higher exposure sensitivity than the first resist are laminated on a magnetic film. 4. The method of manufacturing a magnetic storage medium according to claim 3, wherein the resist pattern of the servo pattern is formed thicker than the resist pattern of the dots by performing exposure with different dose amounts in the data area. Method.
In the resist pattern forming step, a master having a deeper groove than a portion corresponding to the dots in a portion corresponding to the servo pattern on a substrate in which a nonmagnetic film and a resist are laminated on a magnetic film. The method of manufacturing a magnetic storage medium according to claim 3, wherein the resist pattern of the servo pattern is formed thicker than the resist pattern of the dots by pressing.
3. The method of manufacturing a magnetic storage medium according to claim 2, wherein the nonmagnetic film is made of a material mainly composed of any one of chromium, copper, gold, and silver, or an alloy thereof.
3. The method of manufacturing a magnetic storage medium according to claim 2, wherein the magnetic film is made of a material whose main component is one of cobalt, platinum, or an alloy thereof.
Among the magnetic film that forms the servo pattern in the servo area and the magnetic film that forms the dot in the data area, a non-magnetic film arrangement part that arranges the non-magnetic film only on the magnetic film that forms the servo pattern;
A segregation part that segregates nonmagnetic elements at crystal grain boundaries of the magnetic film forming the servo pattern by heating the nonmagnetic film disposed by the nonmagnetic film disposition part,
An apparatus for producing a magnetic storage medium, comprising:
When a resist pattern corresponding to the servo pattern and dots is formed on the nonmagnetic film of the substrate in which a nonmagnetic film is laminated on the magnetic film, the resist of the servo pattern is more than the resist pattern of the dots. It further has a resist pattern forming part that forms a pattern thickly,
The non-magnetic film forming portion is formed on the substrate so that the non-magnetic film on the magnetic film forming the dots is removed and the non-magnetic film is disposed only on the magnetic film forming the servo pattern. The magnetic storage medium manufacturing apparatus according to claim 8, wherein the resist pattern, the nonmagnetic film, and the magnetic film are etched.
The resist pattern forming unit is configured to apply the servo region to a substrate in which a non-magnetic film, a first resist, and a second resist having higher exposure sensitivity than the first resist are stacked on a magnetic film. 10. The apparatus for manufacturing a magnetic storage medium according to claim 9, wherein the resist pattern of the servo pattern is formed thicker than the resist pattern of the dots by performing exposure with different dose amounts in the data area. .
The resist pattern forming portion is a master in which a groove having a deeper groove than a portion corresponding to the dots is dug in a portion corresponding to the servo pattern with respect to a substrate in which a nonmagnetic film and a resist are laminated on a magnetic film. 10. The magnetic storage medium manufacturing apparatus according to claim 9, wherein the resist pattern of the servo pattern is formed thicker than the resist pattern of the dots by pressing.
The apparatus for manufacturing a magnetic storage medium according to claim 8, wherein the non-magnetic film is made of a material mainly composed of any one of chromium, copper, gold, and silver, or an alloy thereof.
9. The magnetic storage medium manufacturing apparatus according to claim 8, wherein the magnetic film is made of a material whose main component is one of cobalt, platinum, or an alloy thereof.
The width in the medium plane direction of the servo pattern in the servo area is formed wider than the width in the medium plane direction of the dots in the data area, and nonmagnetic elements in the crystal grain boundary of the magnetic film forming the servo pattern are formed. An information storage device having a magnetic storage medium having a concentration higher than the concentration of a nonmagnetic element in crystal grains of the magnetic film.