Iridium underlayer for heat assisted magnetic recording media
View Patent ↗A heat-assisted magnetic recording (HAMR) media stack is provided in which Iridium (Ir)-based materials may be utilized as a secondary underlayer instead of a Magnesium Oxide (MgO) underlayer utilized in conventional media stacks. Such Ir-based materials may include, e.g., pure Ir, Ir-based alloys, Ir-based compounds, as well as a granular Ir layer with segregants. The use of Ir or Ir-based materials as an underlayer provide advantages over the use of MgO as an underlayer. For example, DC sputtering can be utilized to deposit the layers of the media stack, where the deposition rate of Ir is considerably higher than that of MgO resulting in higher manufacturing production yields. Further still, less particles are generated during Ir-based layer deposition processes, and Ir-based underlayer can act as a better heat sink. Further still, the morphology and structure of a recording layer deposited on an Ir-based layer can be better controlled.
1. A heat-assisted magnetic recording medium, comprising:
a substrate;
an adhesion layer deposited over the substrate;
a heat sink layer deposited over the adhesion layer;
a first underlayer deposited over the heat sink layer, the first underlayer comprising a body-centered-cubic Co-based material or a body-centered cubic CoFe-based material;
a second underlayer deposited directly over the first underlayer, the second underlayer comprising an Ir-based material; and
a magnetic recording layer for storing data via heat-assisted magnetic recording deposited over the second underlayer.
2. The heat-assisted magnetic recording medium of claim 1 , further comprising an overcoat layer disposed over the magnetic recording layer.
3. The heat-assisted magnetic recording medium of claim 2 , wherein the overcoat layer comprises one of hydrogenated or nitrogenated carbon.
4. The heat-assisted magnetic recording medium of claim 1 , wherein the first underlayer includes an additive comprising at least one of Ni, Zr, B, Ta, W, or Mo.
5. The heat-assisted magnetic recording medium of claim 1 , wherein the heat sink layer comprises (002) Tungsten (W), (002) Ruthenium Aluminide (RuAl), and amorphous Chromium Tantalum (CrTa).
6. The heat-assisted magnetic recording medium of claim 1 , wherein the adhesion layer comprises amorphous Nickel-Tantalum (Ni—Ta).
7. The heat-assisted magnetic recording medium of claim 1 , wherein the substrate comprises one of a glass, metallic, polymer, or ceramic material capable of withstanding temperatures of at least approximately 400° C.-750° C.
8. The heat-assisted magnetic recording medium of claim 1 , wherein the magnetic recording layer is an alloy comprising (001) Iron-Platinum (FePt).
9. The heat-assisted magnetic recording medium of claim 1 , wherein the Ir-based material comprises one of pure Ir, an Ir-based alloy, an Ir-based compound, and a granular Ir layer with segregants.
10. The heat-assisted magnetic recording medium of claim 9 , wherein the Ir-based alloy comprises one of an Iridium Titanium (IrTi) alloy, an Iridium Zirconium (IrZr) alloy, or an Iridium Carbon (IrC) alloy.
11. The heat-assisted magnetic recording medium of claim 9 , wherein the segregants comprise at least one of light and heat absorbing materials.
12. A method, comprising:
generating or providing a substrate;
depositing an adhesion layer over the substrate;
depositing a heat sink layer over the adhesion layer;
depositing a first underlayer over the heat sink layer, the first underlayer comprising a body-centered-cubic Co-based material or a body-centered cubic CoFe-based material;
depositing a second underlayer directly over the first underlayer, the second underlayer comprising an or Ir-based material; and
depositing a recording layer over the second underlayer.
13. The method of claim 12 , wherein the substrate comprises one of a glass, metallic, polymer, or ceramic material capable of withstanding temperatures of at least approximately 400° C.-750° C.
14. The method of claim 12 , wherein the adhesion layer comprises amorphous Nickel-Tantalum (Ni—Ta), and wherein the heat sink layer comprises (002) Tungsten (W), (002) Ruthenium Aluminide (RuAl), and amorphous Chromium Tantalum (CrTa).
15. The method of claim 12 , wherein the recording layer is a heat-assisted magnetic recording (HAMR) recording layer.
16. The method of claim 12 , wherein the recording layer is an alloy comprising (001) Iron-Platinum (FePt).
17. The method of claim 16 , wherein the (001) Iron-Platinum (FePt) alloy comprises a (001) Iron-Platinum (FePt) film having at least a 98 percent correct grain orientation structure.
18. The method of claim 12 , wherein the Ir-based material comprises one of an Ir-based alloy, an Ir-based compound, and a granular Ir layer with segregants.
19. The method of claim 18 , wherein the Ir-based alloy comprises one of an Iridium Titanium (IrTi) alloy, an Iridium Zirconium (IrZr) alloy, or an Iridium Carbon (IrC) alloy.
20. The method of claim 18 , wherein the segregants comprise at least one of light and heat absorbing materials.