Granular perpendicular media interlayer for a storage device
An apparatus and method are provided for improving perpendicular magnetic recording media. The present invention provides media, and a method of fabricating media in a cost-effective manner, with a reduced ruthenium (Ru) content interlayer structure, while meeting media performance requirements. A perpendicular magnetic recording medium is provided comprising a non-magnetic substrate having a surface, and a layer stack situated on the substrate surface. The layer stack comprises, in overlying sequence from the substrate surface a magnetically soft underlayer; an amorphous or crystalline, non-magnetic seed layer; an interlayer structure for crystallographically orienting a layer of a perpendicular magnetic recording material situated on the underlayer; and at least one crystallographically oriented, magnetically hard, perpendicular magnetic recording layer situated on the interlayer structure. The interlayer structure is a stacked structure comprising, in overlying sequence: a chromium alloy situated on the seed layer; and an upper interlayer situated on the chromium alloy.
1. A medium comprising:
a substrate;
a seed layer overlying the substrate, wherein the seed layer is non-magnetic and comprises a nickel based FCC phase alloy;
a chromium alloy interlayer in overlying contact with the seed layer;
an upper interlayer on the chromium alloy interlayer; and
a perpendicular magnetic recording layer overlying the upper interlayer.
2. The medium as in claim 1 , wherein the upper interlayer comprises a ruthenium alloy.
3. The medium as in claim 1 , wherein the upper interlayer is about 2 nm to about 7 nm thick, and wherein further the upper interlayer is operable to create a hexagonal close-packed interface for epitaxial growth of the perpendicular magnetic recording layer.
4. The medium as in claim 2 , wherein the ruthenium alloy is limited to the upper interlayer, and used as a top flash layer.
5. The medium as in claim 1 , wherein the chromium alloy interlayer is of a general formula CrX, wherein X is at least one element selected from the group comprising: Mo, W, Co, Zr, V, Ta, TiO β , SiO β , WO β , NbO β , and TaO β , and wherein in β is within a range of 2 to 3.
6. The medium as in claim 1 , wherein the chromium alloy interlayer is of a general formula CrX, wherein X is at least one element selected from the group consisting of: Mo, W, Co, Zr, V, Ta, TiO β , SiO β , WO β , NbO β , and TaO β , and wherein in β is within a range of 2 to 3.
7. The medium as in claim 1 , wherein the chromium alloy interlayer is about 1 nm to about 15 nm thick.
8. The medium as in claim 1 , wherein the chromium alloy interlayer and the upper interlayer comprise an interlayer structure, and wherein the interlayer structure is a body centered cubic (BCC) structure.
9. The medium as in claim 1 , wherein the perpendicular magnetic recording layer is a granular layer comprising physically separated adjacent grains, and wherein further the perpendicular magnetic recording layer has a hexagonal close-packed (hcp) crystal lattice with a <200> out-of-plane growth orientation.
10. A method comprising:
forming a seed layer overlying a substrate, wherein the seed layer is non-magnetic and comprises a nickel based FCC phase alloy;
forming a chromium alloy interlayer in overlying contact with the seed layer;
forming an upper interlayer on the chromium alloy interlayer; and
forming a perpendicular magnetic recording layer overlying the upper interlayer.
11. The method as in claim 10 , wherein the upper interlayer is formed with a ruthenium alloy.
12. The method as in claim 10 wherein the upper interlayer is formed at about 2 nm to about 7 nm thick, and wherein the upper interlayer is operable to create a hexagonal close-packed interface with <0002> growth orientation for epitaxial growth of the perpendicular magnetic recording layer.
13. The method as in claim 11 , wherein the ruthenium alloy is limited to the upper interlayer, and used as a top flash layer.
14. The method as in claim 10 , wherein the chromium alloy interlayer is of a general formula CrX, wherein X is at least one element selected from the group comprising: Mo, W, Co, Zr, V, Ta, TiO β , SiO β , WO β , NbO β , and TaO β , and wherein in β is within a range of 2 to 3.
15. The method as in claim 10 , wherein the chromium alloy interlayer is of a general formula CrX, wherein X is at least one element selected from the group consisting of: Mo, W, Co, Zr, V, Ta, TiO β , SiO β , WO β , NbO β , and TaO β , and wherein in β is within a range of 2 to 3.
16. The method as in claim 10 , wherein the chromium alloy interlayer is formed at about 1 nm to about 15 nm thick.
17. The method as in claim 10 , wherein the chromium alloy interlayer is sputter deposited at a pressure ranging from 0.5 mtorr to 120 mtorr.
18. The method as in claim 10 , wherein the chromium alloy interlayer and the upper interlayer comprise an interlayer structure, and wherein the interlayer structure is a body centered cubic (BCC) structure.