Method of manufacturing magnetic recording medium, magnetic recording medium, and magnetic recording and reproducing apparatus
View Patent ↗A method of manufacturing a magnetic recording medium, includes at least: forming an orientation control layer 3 that controls orientation of an immediately above layer thereof on a non-magnetic substrate 1 ; and forming a perpendicular magnetic layer 4 in which an easy axis of magnetization is mainly perpendicularly orientated to the non-magnetic substrate 1 , in which the forming of the orientation control layer 3 includes forming a granular layer having a granular structure that includes Ru or a material in which Ru is a main component and an oxide having a melting point which is greater than or equal to 450° C. and less than or equal to 1000° C., by a sputtering method, and the forming of the perpendicular magnetic layer 4 includes growing crystal grains to form columnar crystals that are continuous in a thickness direction together with crystal grains that form the orientation control layer 3.
1. A method of manufacturing a magnetic recording medium, comprising at least:
forming an orientation control layer that controls orientation of an immediately above layer thereof on a non-magnetic substrate; and
forming a perpendicular magnetic layer in which an easy axis of magnetization is mainly perpendicularly orientated to the non-magnetic substrate, in this order from the non-magnetic substrate side,
wherein the forming of the orientation control layer includes:
forming a low gas pressure layer formed of Ru or a material in which R is a main component and not including oxide, and
forming a high gas pressure layer having a granular structure that includes Ru or a material in which Ru is a main component and at least one oxide of B 2 O 3 , In 2 O 3 , Sb 2 O 3 , TeO 2 , by a sputtering method, in this order from the non-magnetic substrate side, and
wherein the forming of the perpendicular magnetic layer includes growing crystal grains to form columnar crystals that are continuous in a thickness direction together with crystal grains that form the orientation control layer.
2. The method of manufacturing the magnetic recording medium according to claim 1 ,
wherein the oxide included in the granular structure is either of B 2 O 3 or In 2 O 3 .
3. The method of manufacturing the magnetic recording medium according to claim 1 ,
wherein the forming of the high pressure layer is performed at a sputtering gas pressure which is greater than or equal to 3 Pa and less than or equal to 6 Pa.
4. The method of manufacturing the magnetic recording medium according to claim 1 ,
wherein the low gas pressure layer is formed in a sputtering gas pressure which is in the range of 0.1 Pa to 3 Pa by a sputtering method, before the forming of the high gas pressure layer, and
wherein the forming of the high gas pressure layer is performed at a sputtering pressure higher than that in the forming of the low gas pressure layer.
5. The method of manufacturing the magnetic recording medium according to claim 1 ,
wherein the high gas pressure layer includes the oxide included in the granular structure in a range of 2 vol. % to 20 vol. % in total.
6. The method of manufacturing the magnetic recording medium according to claim 1 ,
wherein in the forming of the perpendicular magnetic layer, the perpendicular magnetic layer is formed by the sputtering method.
7. The method of manufacturing the magnetic recording medium according to claim 1 ,
wherein the oxide included in the granular structure is B 2 O 3 .
8. The method of manufacturing the magnetic recording medium according to claim 1 , wherein an NiW alloy is used as a material to form a seed layer to control the size of crystal grains of the orientation control layer.
9. The method of manufacturing the magnetic recording medium according to claim 1 ,
wherein the low gas pressure is formed of Ru, and the high gas pressure layer is formed of Ru and B 2 O 3 .