Interlayer comprising chromium-containing alloy
View Patent ↗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 method, comprising:
forming an adhesion layer over a substrate configured to adhere overlying layers to the substrate;
forming a seed layer comprising a face-centered cubic structure over the adhesion layer;
forming a dual-layered interlayer structure comprising a first interlayer and a second interlayer in overlying contact with the seed layer,
wherein forming the interlayer structure comprises sputter deposition of the first interlayer at a first pressure from 0.5 mtorr to 120 mtorr and sputter deposition of the second interlayer over the first interlayer at a second pressure greater than the first pressure,
wherein the first interlayer comprises a chromium-containing alloy, and
wherein the second interlayer comprises a <0002> growth orientation; and
forming a magnetic layer in overlying contact with the interlayer structure.
2. The method of claim 1 ,
wherein the adhesion layer comprises a Ti alloy.
3. The method of claim 1 ,
wherein the first interlayer is about 1 nm to about 15 nm thick, and
wherein the second interlayer is about 2 nm to about 7 nm thick.
4. The method of claim 1 ,
wherein the seed layer comprises a nickel-based, FCC-phase alloy; copper; gold; or silver.
5. The method of claim 1 ,
wherein the adhesion layer comprises a Ti alloy.
6. The method of claim 1 ,
wherein the chromium-containing alloy comprises a body-centered cubic structure,
wherein the chromium-containing alloy further comprises Mo, W, Co, Zr, V, Ta, TiO β , SiO β , WO β , NbO β , or TaO β , and
wherein 2>β≦3.
7. The method of claim 1 ,
wherein the second interlayer comprises a ruthenium-containing alloy, and
wherein the magnetic layer comprises a hexagonal close-packed crystal lattice with a <200> out-of-plane growth orientation.
8. The method of claim 1 ,
wherein the adhesion layer is over a non-textured surface of the substrate.
9. The method of claim 1 ,
wherein the seed layer is configured to facilitate crystal growth of overlying layers.
10. The method of claim 1 , further comprising forming a soft underlayer in overlying contact with the adhesion layer,
wherein the soft underlayer is configured to pass magnetic flux through the soft underlayer in a direction perpendicular to that of magnetic flux through the magnetic layer.
11. The method of claim 1 ,
wherein the second interlayer comprises a ruthenium-containing alloy, and
wherein an X-ray diffraction spectrum for an apparatus formed by the method exhibits a ruthenium peak with a lower intensity in cps than a magnetic peak corresponding to the magnetic layer.
12. The method of claim 1 ,
wherein the second interlayer comprises a ruthenium-containing alloy, and
wherein an X-ray diffraction spectrum for an apparatus formed by the method exhibits a ruthenium peak at an angle greater than about 41° with an intensity of less than about 3000 cps.