MAGNETIC RECORDING MEDIUM AND METHOD OF FABRICATING THE SAME
Provided are a magnetic recording medium and a method of fabricating the same. The magnetic recording medium includes a substrate; and a recording layer, wherein the recording layer is formed of a plurality of magnetic dots, and a non-magnetic region that is formed on the substrate to isolate each of the magnetic dot.
1 . A magnetic recording medium comprising:
a substrate;
a recording layer formed on the substrate;
wherein the recording layer is formed of a plurality of discrete magnetic dots and a non-magnetic region, the non-magnetic region isolating each of the plurality of magnetic dots from each other;
wherein the magnetic dots each have a first surface and a second surface, the second surface being opposite to the first surface, in which the dimension of the first surface is not equal to the dimension of the second surface, and a sidewall of the respective magnetic dots form an angle which is not equal to 90 degrees with respect to the substrate surface.
2 . The magnetic recording medium of claim 1 , wherein a relative ratio of the dimension of the first surface to the dimension of the second surface is 0.9 or less.
3 . The magnetic recording medium of claim 2 , wherein a relative ratio of the dimension of the first surface to the dimension of the second surface is 0.1-0.5.
4 . The magnetic recording medium of claim 1 , wherein the magnetic dots have a truncated cone shape, truncated pyramid shape, a cone shape, reversed truncated cone shape, a reversed truncated pyramid shape.
5 . The magnetic recording medium of claim 1 , wherein the magnetic dots are formed of a material having a magnetic anisotropic constant of 10 5 J/m 3 to 10 7 J/m 3 .
6 . The magnetic recording medium of claim 5 , wherein the magnetic is formed of at least one material selected from the group consisting of CoPt, CoPd, CoNi, CoTb, FePt, FePd, CoFeTb, CoFeGd, CoFeDy, CoFeHo, and CoFeNb.
7 . The magnetic recording medium of claim 1 , wherein the magnetic dots are arranged regularly.
8 . The magnetic recording medium of claim 4 , wherein the magnetic dots may have a combination of different shapes or a single shape.
9 . The magnetic recording medium of claim 1 , wherein the magnetic dots are a laminate of a plurality of layers, in which respective layer has a magnetic anisotropic constant different from the other layers.
10 . The magnetic recording medium of claim 9 , wherein the magnetic dots are formed of a first layer and a second layer, the first layer having a magnetic anisotropic constant of 10 5 J/m 3 to 10 7 J/m 3 and the second layer having a magnetic anisotropic constant of 10 2 J/m 3 to 10 3 J/m 3 .
11 . The magnetic recording medium of claim 10 , wherein the second layer is formed on the substrate and the first layer is formed on the second layer.
12 . The magnetic recording medium of claim 10 , wherein the first layer is formed on the substrate and the second layer is formed on the first layer.
13 . The magnetic recording medium of claim 10 , wherein the first layer is formed of a magnetic material selected from the group consisting of CoPt, CoPd, CoNi, CoTb, FePt, FePd, CoFeTb, CoFeGd, CoFeDy, CoFeHo, and CoFeNb.
14 . The magnetic recording medium of claim 10 , wherein the second layer is formed of a magnetic material selected from the group consisting of NiFe, CoFe, Ni, Fe, Co, and an alloy of these materials.
15 . The magnetic recording medium of claim 1 , further comprising a seed layer, a soft magnetic under layer, and an intermediate layer between the substrate and the recording layer.
16 . The magnetic recording medium of claim 1 , wherein the magnetic dots have perpendicular magnetic anisotropy.
17 . A method of fabricating a magnetic recording medium, comprising:
forming a mold layer on a substrate, the mold layer being non-magnetic;
patterning the mold layer to form a pattern providing a plurality of grooves whose top area dimension is not equal to the dimension of a bottom area; and
filling a magnetic material in the grooves to form magnetic dots which each have the shape of the grooves.
18 . The method of claim 17 , wherein the pattern forms a non-magnetic region that isolates the magnetic dots from each other.
19 . The method of claim 17 , further comprising removing the pattern and applying a non-magnetic material to form a non-magnetic region that isolates the magnetic dots from each other.
20 . The method of claim 17 , wherein the pattern is formed using one method selected from the group consisting of a nano imprint lithography method, a photo lithography method, an E-beam lithography method, a holographic lithography method, and an X-ray lithography method
21 . The method of claim 17 , wherein a relative ratio of the dimension of one of the two surfaces to the dimension of the other surface is 0.9 or less.
22 . The method of claim 21 , wherein the relative ratio of the dimension of one of the two surfaces to the dimension of the other surface is 0.1-0.5.
23 . The method of claim 17 , wherein the magnetic dots have a truncated cone shape, truncated pyramid shape, cone shape, reversed truncated cone shape, or reversed truncated pyramid shape.
24 . The method of claim 17 , wherein the forming of the magnetic dots comprises applying sequentially a plurality of magnetic materials having different magnetic anisotropic constants to form magnetic dots which each are a laminate of plurality of layers.