Vertical magnetic recording medium and manufacturing method thereof
View Patent ↗A magnetic recording medium of higher coercive force and a manufacturing method thereof are provided by enabling reactive sputtering of stable reproducibility even with the addition of oxygen in the formation of a magnetic film using oxygen addition type reactive sputtering. In one embodiment, a vertical magnetic recording medium having SiC and SiO x (x=1 to 2) is provided. Further, a method of manufacturing a vertical magnetic recording medium including the addition of an Ar gas and an oxygen gas to an SiC-containing target in the step of forming a film of a magnetic layer on a soft magnetic under layer by reactive sputtering is provided.
1. A method of manufacturing a magnetic recording medium comprising:
forming a film of an adhesion layer by sputtering on a substrate;
forming a film of a soft magnetic under layer by sputtering on the adhesion layer;
forming a film of a magnetic layer by reactive sputtering on the under layer; and
forming a film of a protective layer by an RF-CVD method on the magnetic layer;
wherein an Ar gas and an oxygen gas are added to an SiC-containing target in forming the film of the magnetic layer.
2. A method of manufacturing a magnetic recording medium according to claim 1 , wherein the substrate has a center line mean roughness of about 0.3 nm or less and a maximum protrusion height of about 5 nm or less.
3. A method of manufacturing a magnetic recording medium according to claim 1 , wherein the soft magnetic under layer has a saturated magnetic flux density in the range of about 0.8 T to 3.0 T.
4. A method of manufacturing a magnetic recording medium according to claim 1 , wherein the soft magnetic under layer has a film thickness in the range of about 50 nm to 300 nm.
5. A method of manufacturing a magnetic recording medium according to claim 1 , wherein the under layer has a film thickness in the range of about 5 nm to 20 nm.
6. A method of manufacturing a magnetic recording medium according to claim 1 , wherein the magnetic layer is a granular layer.
7. A method of manufacturing a magnetic recording medium according to claim 1 , wherein the composition of SiC in the target is in the range of about 5 mol % to 40 mol %.
8. A method of manufacturing a magnetic recording medium according to claim 7 , wherein the composition of SiC in the target is about 10 mol %.
9. A method of manufacturing a magnetic recording medium according to claim 1 , wherein SiC is electroconductive.
10. A method of manufacturing a magnetic recording medium according to claim 1 , wherein the target has CoCrPt.
11. A method of manufacturing a magnetic recording medium according to claim 1 , wherein the gas composition of the oxygen gas to the Ar gas is in the range of about 0.75% to 2%.
12. A method of manufacturing a magnetic recording medium according to claim 1 , wherein the gas composition of the oxygen gas to the Ar gas is about 1.5%.