KR20090115290A - Perpendicular Magnetic Recording Media and Method of Manufacturing the same - Google Patents

Abstract

PURPOSE: A vertical magnetic recording media and a manufacturing method thereof are provided to manufacture a percolate media type and utilize a vertical magnetic recording type. CONSTITUTION: A vertical magnetic recording media and a manufacturing method thereof include a substrate(110) and a recording layer(170). The recording layer is formed by injecting a first magnetic material area(171) as a layer forming the substrate. The recording layer includes a second magnetic material area(173) by the first magnetic area. The second magnetic area does not have the material features.

Description

Perpendicular Magnetic Recording Media and Method of Manufacturing the same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical magnetic recording medium and a method of manufacturing the same, and more particularly, to a vertical magnetic recording medium in which regions having different magnetic properties are formed in a magnetic matrix having vertical magnetic anisotropy, and a method of manufacturing the same.

Recently, there has been a demand for an information storage device capable of recording / reproducing data at a higher density due to a sharp increase in the amount of information. In particular, a magnetic recording apparatus using a recording medium has attracted attention as an information storage device not only for a computer but also for various digital devices due to its large capacity and high-speed access.

Such a magnetic recording apparatus can be largely divided into a horizontal magnetic recording method and a vertical magnetic recording method according to the recording method. The horizontal magnetic recording method records information by using the magnetization direction of the magnetic layer aligned parallel to the surface of the magnetic layer, and the vertical magnetic recording method uses the magnetization direction of the magnetic layer aligned vertically with the surface of the magnetic layer. It is a way of recording information. In terms of recording density, the vertical magnetic recording method is much more advantageous than the horizontal magnetic recording method.

In order to achieve high density recording in the vertical magnetic recording method, the high coercivity and vertical magnetic anisotropy energy of the recording layer, small grain size and small exchange coupling between grains to ensure the stability of the recorded data are achieved. There is a need for a vertical magnetic recording medium having features such as small magnetic domain size.

Conventional vertical magnetic recording media have a granular structure in which an oxide isolates a magnetic granule (magentci granule). The grain size of such a vertical magnetic recording medium decreases gradually as the recording density continues to increase, but a problem may occur in the thermal stability of the vertical magnetic recording medium as the grain size decreases to several nm or less. In addition, the transition length between each bit resulting from a very small grain size limits the further recording density.

To solve this problem, a percolated media structure has been proposed (see J. Zhu and Y. Tang, J. Of Appl. Phys. Vol. 99, p. 08Q903 (2006)). Percolate media are magnetic recording media designed to form oxide sites in a magnetic matrix, such that a transition is formed along these oxide sites. In such percolate media, it is known that if the oxide spreads very evenly over the entire region, the transition length becomes shorter than the granular type.

However, there are many difficulties in the actual implementation of this pecholate media structure. For example, the oxides should be evenly distributed over the entire region, and such oxides should be uniformly present in the columnar shape from the top to the bottom of the recording layer. For example, in the case of using a sputtering method using a metal-oxide target that is commonly employed, there is a problem that the oxide formed is irregularly distributed, and further, the shape of the oxide is spherical.

The present invention provides a percolate medium type vertical magnetic recording medium that is easy to manufacture and a method of manufacturing the same.

A vertical magnetic recording medium according to one aspect of the present invention includes a substrate; And a recording layer formed on the substrate and having magnetic recording, the recording layer comprising a first magnetic region and a plurality of second magnetic regions formed by implanting impurities and separated by the first magnetic region.

The second magnetic region may have a lower perpendicular magnetic anisotropy energy Ku or no magnetic characteristic than the first magnetic region.

The first magnetic region and the second magnetic region may be formed of the same material. For example, the recording layer may be formed of CoPt or FePt.

The first magnetic region may have a crystalline structure, and the second magnetic region may have an amorphous structure.

The first magnetic body region may be in the form of a continuous film or may have an L10 structure.

The second magnetic body region may be distributed at a surface density of 10 ¹² / cm ² to 10 ¹³ / cm ² .

The impurity may be in the form of a molecule having a volume of B _n H _m (n and m are integers, 10 <n, 0 ≦ m ≦ 22) including B (boron).

At least one of a soft magnetic bottom layer, a buffer layer, and an intermediate layer may be further interposed between the substrate and the recording layer.

In addition, a method of manufacturing a vertical magnetic recording medium according to an aspect of the present invention, forming a magnetic layer in the form of a continuous film on a substrate; And injecting impurities into the magnetic layer such that the plurality of second magnetic regions formed by implanting the impurities are separated by the first magnetic region into which the impurities are not implanted.

Before the step of injecting the impurity into the magnetic layer, the magnetic layer may further comprise the step of heat-treating the magnetic layer to crystallize to the L10 structure.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the examples exemplified below are not intended to limit the scope of the present invention, but are provided to fully explain the present invention to those skilled in the art. In the drawings, like reference numerals refer to like elements, and the size of each element in the drawings may be exaggerated for clarity and convenience of description.

1 is a cross-sectional view illustrating a schematic structure of a vertical magnetic recording medium according to an embodiment of the present invention, and FIG. 2 is a diagram schematically illustrating an upper surface of a recording layer.

Referring to FIG. 1, the vertical magnetic recording medium 100 includes a substrate 110, a soft underlay 130, an intermediate layer 150, and a recording layer 170 from below. ), A protection layer 180, and a lubrication layer 190 may be sequentially stacked.

The substrate 110 may be formed of glass, AlMg alloy, AlMg alloy, Si, or the like, and may be manufactured in the shape of a disk.

The soft magnetic bottom layer 130 forms a magnetic path of the vertical magnetic field generated from the magnetic oxygen recording head so that information is recorded in the recording layer, and has a Co-based amorphous structure or includes Fe or Ni. It may be formed of a soft magnetic material. The soft magnetic bottom layer 130 may be formed in a single layer or multiple layers.

The intermediate layer 150 serves to improve crystal orientation and magnetic properties of the recording layer 170 and may be formed of multiple layers. The material forming the intermediate layer is determined according to the recording layer material and its structure, for example, may be formed of Cr alloy or MgO.

A buffer layer (not shown) that suppresses magnetic interaction may be interposed between the substrate 110 and the soft magnetic bottom layer 130 and / or between the soft magnetic bottom layer 130 and the intermediate layer 150. For example, it may be formed of Ti or Ta.

The recording layer 170 is a layer on which magnetic recording is performed. Referring to FIG. 2, the recording layer 170 is divided into first and second magnetic region 171 and 173. The first magnetic region 171 is an area on which the recording layer 170 is based. The plurality of second magnetic body regions 173 are uniformly distributed on the base of the first magnetic body region 171, and are separated from each other by being surrounded by the first magnetic body region 171. As described below, the second magnetic region 173 may be formed to have magnetic properties different from those of the first magnetic region 171 by injecting impurities into the same magnetic material as the first magnetic region 171. The second magnetic region 173 may have a diameter of about 1 nm to 2 nm, and may be distributed at a surface density of about 10 ¹² / cm ² to 10 ¹³ / cm ² . As shown in FIG. 1, the second magnetic region 173 has a columnar shape that penetrates the recording layer 170 when viewed from the side of the recording layer 170.

The first and second magnetic body regions 171 and 173 may be formed of the same material. For example, the first and second magnetic regions 171 and 173 may be formed of CoPt, FePt, or an alloy including the same, and may have different crystal states. The underlying first magnetic region 171 may have a crystalline structure, and the second magnetic region 173 may have an amorphous structure by implanting impurities. As described above, the first and second magnetic regions 171 and 173 have different magnetic properties. The first magnetic body region 171 may have a continuous film form. The first magnetic region 171 may be formed of, for example, CoPt or FePt having an L1 ₀ structure, or CoPt having an hcp structure, and may have high magnetic anisotropy energy Ku. The second magnetic region 173 may have lower perpendicular magnetic anisotropy energy Ku or no magnetic characteristics than the first magnetic region 171 due to impurity implantation. For example, the magnetic anisotropy energy Ku of the first magnetic region 171 may be 10 ⁵ J / m ³ to 10 ⁸ J / m ³ , and the magnetic anisotropic energy of the second magnetic region 173 ( Ku) may be 10 ⁴ J / m ³ or less. As described above, the phenomenon in which the magnetic anisotropy energy is reduced or the magnetism is lost due to the impurity injection may be understood as a phenomenon in which the crystallinity of the magnetic body is mainly broken by the impurities. The impurity may be in the form of a molecule such as B (boron) containing a certain volume of B _n H _m (n and m are integers, 10 <n, 0 ≦ m ≦ 22). Boron hydride molecules such as, for example, Octadecaborane (B ₁₈ H ₂₂ ) molecules may be used as impurities.

Although not shown, the recording layer 170 may be formed of multiple layers, and at least one of the multilayers may have a structure of first and second magnetic region.

Referring back to FIG. 1, the protective layer 180 is to protect the recording layer 170 from the outside and may be formed of diamond-like carbon (DLC), and the magnetic layer may be formed on the protective layer 180. In order to reduce wear of the head and the protective layer due to impact and sliding, a lubrication layer 190 may be formed of a teraol lubricant or the like.

3A to 3C are cross-sectional views illustrating a manufacturing process of a vertical magnetic recording medium according to an embodiment of the present invention.

Referring to FIG. 3A, the soft magnetic bottom layer 230, the intermediate layer 250, and the magnetic layer 271 are sequentially formed on the substrate 210. The soft magnetic bottom layer 230 is formed of FeSi. The intermediate layer 250 is formed of MgO. The magnetic layer 271 is formed by crystallizing CoPt in a continuous film form by a sputtering method.

Referring to FIG. 3B, octadecaborane (B ₁₈ H ₂₂ ) molecules are injected at a dose of 10 ¹² / cm ² to 10 ¹³ / cm ² into the magnetic layer 271 crystallized in the form of a continuous film. The method of infusion does not limit the invention. Since the process of injecting the octadecarborane molecule is well known in the art as a process used in a conventional semiconductor process, a detailed description thereof will be omitted. As described above, the octadecarborane molecule is an example of an impurity that causes a magnetic change of the magnetic layer 271, but the present invention is not limited thereto. When the impurity is injected into the magnetic layer 271, it is possible to change the magnetic properties of the passing position, and the impurity is a molecule having a certain volume and may be a molecule that can be used in the implantation process.

Since the present embodiment does not employ a lithography process using a separate mask or the like to form the second magnetic body region 273, the manufacturing process is simple. In addition, by forming the second magnetic region 273 by injecting nano-sized molecules, it is possible to easily achieve a fine structure.

Referring to FIG. 3C, the magnetic layer 271 of the region where the octadecarborane molecule is not injected remains crystallized in the form of an initial continuous film to form a first magnetic region, and the position through which the octadecarborane molecule passes causes a magnetic change. The second magnetic region 273 is formed. The second magnetic region 273 causing the magnetic change may have low magnetic anisotropy energy Ku or disappear magnetic properties. The octadecarborane molecules are injected with sufficient energy perpendicular to the magnetic layer 271 to form the second magnetic region 273 in the shape of a column passing through the recording layer 270 when viewed from the side of the recording layer 270. You can. Since the octadecarborane molecule has a size of approximately 1 nm, the second magnetic region 273 has a diameter of approximately 1 nm to a size slightly larger than that, and the frequency is approximately corresponding to the injection dose of the octadecarborane molecule. 10 ¹² / cm ² to 10 ¹³ / cm ² . The size and frequency of the second magnetic region 273 can be controlled by changing the type of impurity implanted, the dose of the impurity or the implantation energy.

 Next, a process of forming a protective layer and a lubricating layer (not shown) on the recording layer 270 may be continued, and since the processes well known in the art may be adopted as they are, detailed description thereof will be omitted.

4A to 4D are cross-sectional views illustrating a manufacturing process of a vertical magnetic recording medium according to another embodiment of the present invention.

Referring to FIG. 4A, the soft magnetic bottom layer 330, the intermediate layer 350, and the magnetic layer 371 are sequentially formed on the substrate 310. The soft magnetic bottom layer 330 is formed of FeSi, and the intermediate layer 350 is formed of MgO. The magnetic layer 371 forms FePt in a continuous film form by a sputtering method.

Referring to FIG. 4B, a heat treatment is applied to the magnetic layer (371 of FIG. 4A) formed in the form of the continuous film to crystallize into a magnetic layer 371 ′ having an L1 ₀ structure. In the case of the conventional vertical magnetic recording medium, while it is very small grain size in crystallization L1 ₀ structure is known to be difficult. However, since the magnetic layer 371 'of the vertical magnetic recording medium of this embodiment has a L1 ₀ structure in the form of a continuous film instead of a granular structure, it can be easily crystallized into an L1 ₀ structure at a low temperature. In the present exemplary embodiment, the magnetic layer 371 ′ having the L1 ₀ structure is formed through a heat treatment process, but is not limited thereto. For example, the magnetic layer 371 ′ having the L1 ₀ structure may be formed by first heating the substrate 310 and depositing a FePt layer to crystallize the L1 ₀ structure before the heated substrate 310 is cooled. Alternatively, the FePt layer is deposited by sputtering at a temperature of 350 ° C. to crystallize into a L1 ₀ structure in the form of a continuous film, thereby forming a magnetic layer 371 ′ having a L1 ₀ structure.

Next, referring to FIGS. 4C and 4D, doses of octadecaborane (B ₁₈ H ₂₂ ) molecules 10 ¹² / cm ² to 10 ¹³ / cm ² in the magnetic layer 371 ′ crystallized to the L1 ₀ structure ) The magnetic layer 371 in the region where the octadecarborane molecule is not injected remains crystallized in the L1 ₀ structure to form the first magnetic region, and the position where the octadecaborane molecule has passed is the second magnetic region in which the L1 ₀ structure is broken. (373) is formed. The second magnetic region 373 having a broken L1 ₀ structure may have low magnetic anisotropy (Ku) or disappear magnetic properties. Since the shape, size, and frequency of the second magnetic region 373 are substantially the same as in the above-described embodiment, description thereof will be omitted.

Next, a process of forming a protective layer and a polishing layer (not shown) on the recording layer 370 may be continued.

Such a vertical magnetic recording medium and a method of manufacturing the present invention have been described with reference to the embodiments shown in the drawings for clarity of understanding, but these are merely illustrative, and those skilled in the art can various modifications and It will be appreciated that other equivalent embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

1 is a cross-sectional view showing a schematic structure of a vertical magnetic recording medium according to an embodiment of the present invention.

FIG. 2 is a diagram showing the structure of a recording layer of the vertical magnetic recording medium of FIG.

3A to 3C are cross-sectional views illustrating a manufacturing process of a vertical magnetic recording medium according to an embodiment of the present invention.

4A to 4D are cross-sectional views illustrating a manufacturing process of a vertical magnetic recording medium according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100 ... Vertical Magnetic Recording Media 110 ... Substrate

130 ... soft magnetic floor layer 150 ... middle layer

170 recording layer 171 first magnetic region

173 .Second layer of magnetic material 180 ... protective layer

190.Lubrication layer

Claims (20)

Board; And And a recording layer formed on the substrate to perform magnetic recording, wherein the recording layer includes a first magnetic region and a plurality of second magnetic region formed by implanting impurities and separated by the first magnetic region. Recording media. According to claim 1, And the second magnetic region has a lower perpendicular magnetic anisotropy energy (Ku) or no magnetic characteristic than the first magnetic region. According to claim 1, And the first magnetic region and the second magnetic region are formed of the same material. The method of claim 3, wherein And the first magnetic region has a crystalline structure, and the second magnetic region has an amorphous structure. According to claim 1, And the recording layer is formed of CoPt or FePt. The method according to any one of claims 1 to 5, And the first magnetic region is in the form of a continuous film. The method according to any one of claims 1 to 5, And said first magnetic region has an L10 structure. The method according to any one of claims 1 to 5, And the second magnetic region is distributed at a surface density of 10 ¹² / cm ² to 10 ¹³ / cm ² . The method according to any one of claims 1 to 5, And the second magnetic region has a size of 0.5 nm to 2 nm in diameter. The method according to any one of claims 1 to 5, And the impurity is in molecular form. The method according to any one of claims 1 to 5, And at least one of a soft magnetic bottom layer, a buffer layer, and an intermediate layer is further interposed between the substrate and the recording layer. Forming a magnetic layer in the form of a continuous film on the substrate; And Implanting impurities into the magnetic layer such that the plurality of second magnetic region formed by implanting the impurity is separated by the first magnetic region not implanted with the impurity; The method of claim 12, And the second magnetic region has a lower perpendicular magnetic anisotropy energy (Ku) or no magnetic property than the first magnetic region. The method of claim 12, And the first magnetic region and the second magnetic region are formed of the same material. The method of claim 14, Wherein the first magnetic region is formed of a crystalline structure, and the second magnetic region is formed of an amorphous structure. The method of claim 14, And the magnetic layer is formed of CoPt or FePt. The method of claim 12, Forming a magnetic layer in the form of a continuous film on the substrate, And the magnetic layer is formed into an L10 structure. The method of claim 12, And the impurity is implanted in the form of ions or molecules. The method of claim 18, And wherein said impurity is a boron hydride molecule. The method of claim 18, And the impurity is injected at a dose of 10 ¹² / cm ² to 10 ¹³ / cm ² .

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