MAGNETIC RECORDING MEDIA WITH SMALL RECORDING GRAIN SIZES, HIGH ASPECT RATIO, AND METHODS OF FABRICATING SAME
Various apparatuses, systems, methods, and media are disclosed to provide a heat-assisted magnetic recording (HAMR) medium having small recording grain sizes with high aspect ratio. One example magnetic recording medium includes, a substrate, a heat sink layer on the substrate, an underlayer comprising MgO—TiO on the heat sink layer, an interfacial layer comprising TiN on the underlayer, a first nucleation layer on the interfacial layer and comprising FePt—Ag—X, wherein X is an oxide, a second nucleation layer on the first nucleation layer and comprising FePt—Ag—Y, wherein Y is an oxide or a nitride, and a magnetic recording layer on the second nucleation layer. In another example, the TiN is formed as a part of the underlayer rather than in the interfacial layer.
1 . A magnetic recording medium comprising:
a substrate;
a heat sink layer on the substrate;
an underlayer comprising MgO—TiO on the heat sink layer;
an interfacial layer comprising TiN on the underlayer;
a first nucleation layer on the interfacial layer and comprising FePt—Ag—X, wherein X is an oxide;
a second nucleation layer on the first nucleation layer and comprising FePt—Ag—Y, wherein Y is an oxide or a nitride; and
a magnetic recording layer on the second nucleation layer.
2 . The magnetic recording medium of claim 1 , wherein the TiN of the interfacial layer is formed of Ti from the underlayer and N2 during sputtering of the first nucleation layer.
3 . The magnetic recording medium of claim 1 , wherein Y is an oxide.
4 . The magnetic recording medium of claim 3 , wherein Y comprises at least one of SiO2, TiO2, Cr2O3, ZrO2, Al2O3, Fe2O3, or Ta2O5.
5 . The magnetic recording medium of claim 1 , wherein Y is SiO2 and X is SiO2.
6 . The magnetic recording medium of claim 1 , wherein Y is a nitride.
7 . The magnetic recording medium of claim 6 , wherein Y comprises at least one of Si3N4, TiN, CrN, TaN, ZrN, or VN.
8 . The magnetic recording medium of claim 1 , wherein a mole percent of Ag in the second nucleation layer is in the range of 0.1 to 12.
9 . The magnetic recording medium of claim 1 , wherein the first nucleation layer comprises N.
10 . The magnetic recording medium of claim 1 , wherein:
the interfacial layer is directly on the underlayer;
the first nucleation layer is directly on the interfacial layer;
the second nucleation layer is directly on the first nucleation layer; and
the magnetic recording layer is directly on the second nucleation layer.
11 . A magnetic recording medium comprising:
a substrate;
a heat sink layer on the substrate;
a underlayer on the heat sink layer and comprising MgO—TiO (MTO) and TiN;
a first nucleation layer on the underlayer and comprising FePt—Ag—X, wherein X is an oxide;
a second nucleation layer on the first nucleation layer and comprising FePt—Ag—Y, wherein Y is an oxide or a nitride; and
a magnetic recording layer on the second nucleation layer,
wherein the underlayer comprises a first surface and a second surface closer to the first nucleation layer than the first surface; and
wherein a concentration of the TiN in the underlayer is higher at the second surface than at the first surface.
12 . The magnetic recording medium of claim 11 , wherein the TiN of the underlayer is formed of Ti from the MTO and N gas used during sputtering of the first nucleation layer.
13 . The magnetic recording medium of claim 11 , wherein Y is an oxide.
14 . The magnetic recording medium of claim 13 , wherein Y comprises at least one of SiO2, TiO2, Cr2O3, ZrO2, Al2O3, Fe2O3, or Ta2O5.
15 . The magnetic recording medium of claim 11 , wherein Y is SiO2 and X is SiO2.
16 . The magnetic recording medium of claim 11 , wherein Y is a nitride.
17 . The magnetic recording medium of claim 16 , wherein Y comprises at least one of Si3N4, TiN, CrN, TaN, ZrN, or VN.
18 . The magnetic recording medium of claim 11 , wherein a mole percent of Ag in the second nucleation layer is in the range of 0.1 to 12.
19 . The magnetic recording medium of claim 11 , wherein the first nucleation layer comprises N2.
20 . The magnetic recording medium of claim 11 , further comprising:
a thermal barrier layer directly on the heat sink layer;
wherein the underlayer is directly on the thermal barrier layer;
wherein the first nucleation layer is directly on the underlayer;
wherein the second nucleation layer is directly on the first nucleation layer; and
wherein the magnetic recording layer is directly on the second nucleation layer.
21 . A method for fabricating a magnetic recording medium, the method comprising:
providing a substrate;
providing a heat sink layer on the substrate;
providing an underlayer comprising MgO—TiO (MTO) on the heat sink layer;
sputtering a first nucleation layer, comprising FePt—Ag—X where X is an oxide, on the underlayer using a N2 deposition gas, wherein N2 from the N2 deposition gas and Ti from the MTO of the underlayer form TiN;
sputtering a second nucleation layer, comprising FePt—Ag—Y where Y is an oxide or a nitride, on the first nucleation layer; and
providing a magnetic recording layer on the second nucleation layer.
22 . The method of claim 21 , wherein the TiN forms a layer between the underlayer and the first nucleation layer.
23 . The method of claim 21 :
wherein the underlayer comprises a first surface and a second surface closer to the first nucleation layer than the first surface; and
wherein the TiN forms such that a concentration of the TiN is higher at the second surface than at the first surface.
24 . The method of claim 21 , wherein Y is SiO2 and X is SiO2.
25 . The method of claim 21 , wherein the second nucleation layer is sputtered using an Ar deposition gas.
26 . A magnetic recording medium formed using a process comprising:
providing a substrate;
providing a heat sink layer on the substrate;
providing an underlayer comprising MgO—TiO (MTO) on the heat sink layer;
sputtering a first nucleation layer, comprising FePt—Ag—X where X is an oxide, on the underlayer using a N2 deposition gas, wherein N2 from the N2 deposition gas and Ti from the MTO of the underlayer form TiN;
sputtering a second nucleation layer, comprising FePt—Ag—Y where Y is an oxide or a nitride, on the first nucleation layer; and
providing a magnetic recording layer on the second nucleation layer.
27 . The magnetic recording medium formed using the process of claim 26 , wherein the TiN forms a layer between the underlayer and the first nucleation layer.