Bi-layer NFT-core spacer for EAMR system and method of making the same
View Patent ↗Embodiments of the present invention are directed toward a bi-layer spacer structure and related fabrication processes for improving an interface between a near-field transducer (NFT) and a spacer on an optical waveguide core for an energy assisted magnetic recording (EAMR) system. The embodiments provide a solution for improving the adhesion between the NFT and the spacer.
1. An energy assisted magnetic recording (EAMR) apparatus comprising:
an optical waveguide core configured to direct light to a first end thereof;
a near-field transducer (NFT) positioned adjacent to the first end of the optical waveguide core; and
a bi-layer spacer positioned between the NFT and the optical waveguide core, the bi-layer spacer comprising a first spacer layer and an oxide cap layer consisting of a metal oxide or a combination of metal oxides, wherein the metal oxide or the combinations of metal oxides is completely oxidized.
2. The EAMR apparatus of claim 1 , wherein the first spacer layer comprises SiO2.
3. The EAMR apparatus of claim 1 , wherein the NFT comprises a material selected from the group consisting of gold (Au) and a Au alloy.
4. The EAMR apparatus of claim 1 , wherein the oxide cap layer of the bi-layer spacer comprises a material selected from the group consisting of Ta2O5, TiO2, and combinations thereof.
5. The EAMR apparatus of claim 1 , wherein the oxide cap layer of the bi-layer spacer is positioned closer to the NFT than to the optical waveguide core.
6. The EAMR apparatus of claim 1 , wherein the oxide cap layer of the bi-layer spacer is in contact with the NFT, and the first spacer layer of the bi-layer spacer is in contact with the optical waveguide core.
7. The EAMR apparatus of claim 1 , wherein the oxide cap layer of the bi-layer spacer is in contact with a side of the NFT, and the oxide cap layer has a shape substantially the same as that of the side of the NFT.
8. The EAMR apparatus of claim 1 , further comprising a writer pole on the NFT and a heat dissipator between the writer pole and the NFT.
9. The EAMR apparatus of claim 1 , further comprising a first cladding layer on at least a portion of the bi-layer spacer.
10. The EAMR apparatus of claim 9 , further comprising a second cladding layer, wherein the optical waveguide core is between the second cladding layer and the bi-layer spacer.
11. The EAMR apparatus of claim 1 , wherein the oxide cap layer of the bi-layer spacer has a thickness between about 1 nm and about 5 nm, inclusive.
12. The EAMR apparatus of claim 11 , wherein the oxide cap layer of the bi-layer spacer has a thickness of about 2 nm.
13. The EAMR apparatus of claim 1 , wherein the NFT has a thickness between about 30 nm and about 80 nm, inclusive.
14. The EAMR apparatus of claim 1 , wherein the first spacer layer of the bi-layer spacer has a thickness between about 8 nm and about 12 nm, inclusive.
15. The EAMR apparatus of claim 14 , wherein the first spacer layer of the bi-layer spacer has a thickness of about 10 nm.
16. A method of manufacturing an EAMR apparatus, the method comprising:
forming a first cladding layer;
forming an optical waveguide layer on the first cladding layer;
forming a first spacer layer on the optical waveguide layer;
forming an oxide cap layer consisting of a metal oxide or a combination of metal oxides on the first spacer layer, the oxide cap layer and the first spacer layer forming a bi-layer spacer layer; and
forming a near-field transducer layer on the oxide cap layer,
wherein the metal oxide or the combinations of metal oxides is completely oxidized.
17. The method of claim 16 , wherein the first spacer layer comprises SiO2.
18. The method of claim 16 , wherein the forming the near-field transducer layer comprises patterning the near-field transducer layer to form a near-field transducer (NFT) positioned adjacent to an end of the optical waveguide layer.
19. The method of claim 18 , wherein the forming the oxide cap layer comprises patterning the oxide cap layer such that the oxide cap layer has a shape substantially the same as the NFT.
20. The method of claim 19 , further comprising:
forming a second cladding layer on both the bi-layer spacer layer and the NFT; and
shaping a portion of the second cladding layer to form a sloped portion on the NFT.
21. The method of claim 20 , further comprising forming a writer pole on both the second cladding layer and the NFT.
22. The method of claim 16 , wherein the near-field transducer layer comprises a material selected from the group consisting of gold (Au) and a Au alloy.
23. The method of claim 16 , wherein the optical waveguide layer comprises a core comprising Ta2O5.
24. The method of claim 16 , wherein the oxide cap layer comprises a material selected from the group consisting of Ta2O5, TiO2, and combinations thereof.
25. The method of claim 16 , further comprising:
forming a hard mask layer on the near-field transducer layer;
patterning the hard mask layer to expose a portion of the near-field transducer layer;
removing the exposed portion of the near-field transducer layer to form a near field transducer (NFT); and
removing an exposed portion of the oxide cap layer of the bi-layer spacer layer such that the remaining portion of the oxide cap layer is between the NFT and the first spacer layer of the bi-layer spacer layer.
26. The method of claim 25 , wherein the NFT has a pin portion having a first end and a second end adjacent to an end of the optical waveguide layer, and a disc portion attached to the first end of the pin portion.
27. The method of claim 25 , wherein the oxide cap layer of the bi-layer spacer layer has a thickness between about 1 nm and about 5 nm, inclusive.
28. The method of claim 27 , wherein the oxide cap layer of the bi-layer spacer layer has a thickness of about 2 nm.
29. The method of claim 25 , wherein the NFT has a thickness between about 30 nm and about 80 nm, inclusive.
30. The method of claim 25 , wherein the first spacer layer of the bi-layer spacer layer has a thickness of about 10 nm.
31. The EAMR apparatus of claim 1 :
wherein the NFT comprises a preselected shape that is substantially flat; and
wherein the bi-layer spacer comprises a preselected shape that is substantially flat.
32. The EAMR apparatus of claim 31 :
wherein the preselected shape of the NFT comprises a disc portion; and
wherein the preselected shape of the bi-layer spacer comprises a disc portion.
33. The method of claim 18 :
wherein the NFT comprises a preselected shape that is substantially flat; and
wherein the bi-layer spacer comprises a preselected shape that is substantially flat.
34. The method of claim 33 :
wherein the preselected shape of the NFT comprises a disc portion; and
wherein the preselected shape of the bi-layer spacer comprises a disc portion.
35. An energy assisted magnetic recording (EAMR) apparatus comprising:
an optical waveguide core configured to direct light to a first end thereof;
a near-field transducer (NFT) positioned adjacent to the first end of the optical waveguide core; and
a bi-layer spacer positioned between the NFT and the optical waveguide core, the bi-layer spacer comprising a first spacer layer and an oxide cap layer consisting of a metal oxide or a combination of metal oxides, wherein the metal oxide or the combinations of metal oxides is completely oxidized;
wherein the first spacer layer comprises SiO2;
wherein the NFT comprises a material selected from the group consisting of gold (Au) and a Au alloy;
wherein the preselected shape of the NFT comprises a disc portion; and
wherein the preselected shape of the bi-layer spacer comprises a disc portion.