Perpendicular magnetic recording medium

Abstract

A perpendicular magnetic recording medium has a substrate, a soft magnetic underlayer formed on the substrate, arrayed soft magnetic dots formed on the soft magnetic underlayer, and a ferromagnetic recording layer formed on the soft magnetic dots and having magnetic anisotropy in a direction perpendicular to a surface of the substrate.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-282439, filed Sep. 27, 2002, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a perpendicular magnetic recording medium capable of achieving high-density magnetic recording.

[0004] 2. Description of the Related Art

[0005] For performing high-density magnetic recording, it is necessary to reduce the size of magnetic domains, each of which is a recording unit of information. In the perpendicular magnetic recording medium that is generally used nowadays, information is recorded in a magnetic thin film containing magnetically disrupted magnetic grains. In order to reduce the size of the magnetic domains and to discriminate boundaries thereof for the high-density magnetic recording, it is necessary to reduce ...

Examples

first embodiment

[0032]FIG. 1 is a cross-sectional view showing the structure of a perpendicular magnetic recording medium according to a first embodiment of the present invention. As shown in FIG. 1, the perpendicular magnetic recording medium comprises a substrate 11, a soft magnetic underlayer 12 formed on the substrate 11, arrayed soft magnetic dots 14 formed on the soft magnetic underlayer 12, a ferromagnetic recording layer 15 formed on the soft magnetic dots 14 and having magnetic anisotropy in a direction perpendicular to the surface of the substrate 11. In the embodiment shown in the drawing, an intermediate layer 13 is embedded between adjacent soft magnetic dots 14 and is interposed between the soft magnetic dots 14 and the ferromagnetic recording layer 15. The upper surface of the intermediate layer 13 is planarized so as to lower the flying height of the head. It is desirable for the flatness to be 10 nm or less, preferably 5 nm or less, and more preferably 3 nm or less in terms of the ...

second embodiment

[0058]FIG. 5 is a cross-sectional view showing the structure of the perpendicular magnetic recording medium according to a second embodiment of the present invention. As shown in the drawing, the perpendicular magnetic recording medium comprises a substrate 11, a soft magnetic underlayer 12 formed on the substrate 11, a nonmagnetic intermediate layer 53 formed on the soft magnetic underlayer 12, a ferromagnetic recording layer 55 formed on the nonmagnetic intermediate layer 53 and having magnetic anisotropy in a direction perpendicular to the upper surface of the substrate 11, and arrayed soft magnetic dots 54 formed on the ferromagnetic recording layer 55. Incidentally, the portions equal to those in FIG. 1 are denoted by the same reference numerals.

[0059] In the perpendicular magnetic recording medium according to the second embodiment, the soft magnetic dots 54 are formed on the ferromagnetic recording layer 55. The function performed by the particular perpendicular magnetic rec...

third embodiment

[0066]FIG. 9 is a cross-sectional view showing the structure of a perpendicular magnetic recording medium according to a third embodiment of the present invention. As shown in the drawing, the perpendicular magnetic recording medium a substrate 11, a soft magnetic underlayer 12 formed on the substrate 11, a nonmagnetic layer 53 formed on the soft magnetic underlayer 12, arrayed ferromagnetic recording regions 75a defined by grooves 75b engraved in a ferromagnetic layer formed on the nonmagnetic layer 53, each ferromagnetic recording region 75a having magnetic anisotropy in a direction perpendicular to a surface of the substrate 11, and arrayed soft magnetic dots 54 formed on the respective ferromagnetic recording regions 75a.

[0067] In the perpendicular magnetic recording medium according to the third embodiment, the surface of the ferromagnetic recording layer 75 is processed so as to form the grooves 75b, thereby forming ferromagnetic recording regions 75a. By processing a part of...

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-282439, filed Sep. 27, 2002, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a perpendicular magnetic recording medium capable of achieving high-density magnetic recording.

[0004] 2. Description of the Related Art

[0005] For performing high-density magnetic recording, it is necessary to reduce the size of magnetic domains, each of which is a recording unit of information. In the perpendicular magnetic recording medium that is generally used nowadays, information is recorded in a magnetic thin film containing magnetically disrupted magnetic grains. In order to reduce the size of the magnetic domains and to discriminate boundaries thereof for the high-density magnetic recording, it is necessary to reduce ...

Examples

first embodiment

[0032]FIG. 1 is a cross-sectional view showing the structure of a perpendicular magnetic recording medium according to a first embodiment of the present invention. As shown in FIG. 1, the perpendicular magnetic recording medium comprises a substrate 11, a soft magnetic underlayer 12 formed on the substrate 11, arrayed soft magnetic dots 14 formed on the soft magnetic underlayer 12, a ferromagnetic recording layer 15 formed on the soft magnetic dots 14 and having magnetic anisotropy in a direction perpendicular to the surface of the substrate 11. In the embodiment shown in the drawing, an intermediate layer 13 is embedded between adjacent soft magnetic dots 14 and is interposed between the soft magnetic dots 14 and the ferromagnetic recording layer 15. The upper surface of the intermediate layer 13 is planarized so as to lower the flying height of the head. It is desirable for the flatness to be 10 nm or less, preferably 5 nm or less, and more preferably 3 nm or less in terms of the ...

second embodiment

[0058]FIG. 5 is a cross-sectional view showing the structure of the perpendicular magnetic recording medium according to a second embodiment of the present invention. As shown in the drawing, the perpendicular magnetic recording medium comprises a substrate 11, a soft magnetic underlayer 12 formed on the substrate 11, a nonmagnetic intermediate layer 53 formed on the soft magnetic underlayer 12, a ferromagnetic recording layer 55 formed on the nonmagnetic intermediate layer 53 and having magnetic anisotropy in a direction perpendicular to the upper surface of the substrate 11, and arrayed soft magnetic dots 54 formed on the ferromagnetic recording layer 55. Incidentally, the portions equal to those in FIG. 1 are denoted by the same reference numerals.

[0059] In the perpendicular magnetic recording medium according to the second embodiment, the soft magnetic dots 54 are formed on the ferromagnetic recording layer 55. The function performed by the particular perpendicular magnetic rec...

third embodiment

[0066]FIG. 9 is a cross-sectional view showing the structure of a perpendicular magnetic recording medium according to a third embodiment of the present invention. As shown in the drawing, the perpendicular magnetic recording medium a substrate 11, a soft magnetic underlayer 12 formed on the substrate 11, a nonmagnetic layer 53 formed on the soft magnetic underlayer 12, arrayed ferromagnetic recording regions 75a defined by grooves 75b engraved in a ferromagnetic layer formed on the nonmagnetic layer 53, each ferromagnetic recording region 75a having magnetic anisotropy in a direction perpendicular to a surface of the substrate 11, and arrayed soft magnetic dots 54 formed on the respective ferromagnetic recording regions 75a.

[0067] In the perpendicular magnetic recording medium according to the third embodiment, the surface of the ferromagnetic recording layer 75 is processed so as to form the grooves 75b, thereby forming ferromagnetic recording regions 75a. By processing a part of...

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