Systems and methods for forming magnetic recording media with improved grain columnar growth for energy assisted magnetic recording
View Patent ↗Systems and methods for forming magnetic recording media with improved columnar growth for energy assisted magnetic recording are provided. In one such method, a first sub-layer of a magnetic layer is formed on a substrate, the magnetic layer including a magnetic material and a plurality of non-magnetic segregants, a top surface of the first sub-layer is etched to substantially remove the non-magnetic segregants accumulated on the top surface, and a second sub-layer of the magnetic layer is formed on the first sub-layer.
1. A method for fabricating a magnetic recording medium to increase a thickness of a magnetic recording layer of the magnetic recording medium, the method comprising:
forming a first sub-layer of the magnetic recording layer on a substrate, the magnetic recording layer comprising a magnetic material and a plurality of non-magnetic segregants, wherein the forming the first sub-layer of the magnetic recording layer causes the non-magnetic segregants to accumulate over the magnetic material and at a top surface of the first sub-layer;
etching the top surface of the first sub-layer to remove substantially all of the non-magnetic segregants accumulated at the top surface; and
forming a second sub-layer of the magnetic recording layer on the first sub-layer.
2. The method of claim 1 , wherein the forming of the second sub-layer of the magnetic recording layer comprises continuing a columnar crystal growth of the magnetic recording material from the first sub-layer.
3. The method of claim 1 , wherein the etching the top surface of the first sub-layer comprises removing a portion of the first sub-layer proximate to the top surface.
4. The method of claim 3 , wherein the portion of the first sub-layer proximate to the top surface has a concentration of the non-magnetic segregants higher than that of the other portions of the first sub-layer.
5. The method of claim 1 , wherein the etching is performed by an etching process selected from the group consisting of inductively coupled plasma (ICP) etching, ion milling, sputter etching, reactive ion etching, and combinations thereof.
6. The method of claim 5 :
wherein the etching is performed by inductively coupled plasma (ICP) etching; and
wherein the ICP etching is performed with an ICP etch gas mixture selected from the group consisting of Ar, H 2 , O 2 , Xe, Ne, and N 2 .
7. The method of claim 1 , wherein the magnetic recording material comprises a material selected from the group consisting of Fe, Co, Ni, and combinations thereof.
8. The method of claim 7 , wherein the magnetic recording material comprises FePt.
9. The method of claim 1 , wherein the plurality of non-magnetic segregants comprise a material selected from the group consisting of C, Cr, B, SiO 2 , TiO 2 , Cr 2 O 3 , Ag, BN, V 2 O 5 , ZrO 2 , Nb 2 O 5 , HfO 2 , Ta 2 O 5 , WO 3 , MgO, B 2 O 3 , ZnO, and combinations thereof.
10. The method of claim 9 , wherein the plurality of non-magnetic segregants comprise carbon.
11. The method of claim 1 , wherein the magnetic recording material has grain sizes between about 4 nm and about 9 nm in diameter, inclusive.
12. The method of claim 11 , wherein the magnetic recording material has grain sizes between about 5 nm and about 6 nm in diameter, inclusive.
13. The method of claim 1 , wherein the first sub-layer has a thickness between about 3 nm and about 6 nm, inclusive, and the second sub-layer has a thickness between about 3 nm and about 10 nm, inclusive.
14. The method of claim 13 , wherein the first sub-layer of the magnetic recording layer has a thickness between about 3 nm and about 4 nm, inclusive.
15. The method of claim 1 , further comprising:
etching a top surface of the second sub-layer to substantially remove the non-magnetic segregants accumulated at the top surface of the second sub-layer; and
forming a third sub-layer of the magnetic layer on the second sub-layer.
16. The method of claim 1 , wherein a ratio of a thickness of the magnetic recording layer to a grain diameter of the magnetic material is greater than 1.
17. The method of claim 1 , further comprising forming, between the magnetic recording layer and the substrate, an adhesion layer on the substrate, a heat sink layer on the adhesion layer, and an under-layer on the heat sink layer.
18. The method of claim 1 , further comprising forming a protective coating layer directly on the second sub-layer.
19. The method of claim 1 , wherein the magnetic recording layer is configured to record information.