Method for use in forming a read sensor for a magnetic head
View Patent ↗Methods for use in forming a CPP read sensor for a magnetic head are disclosed. In a particular example, a plurality of read sensor layers are formed over a first shield layer and a resist without undercuts is formed over the plurality of read sensor layers in a central region. With the resist in place, read sensor materials in side regions adjacent the central region are removed by milling to thereby form a read sensor structure in the central region. Insulator materials and metallic seed materials are then deposited in the side regions. High angle ion milling is performed to reduce a thickness of the insulator materials, the metallic seed materials, or both, along sidewalls of the read sensor structure. Magnetic hard bias materials are subsequently deposited over the metallic seed materials, and a second shield layer is formed over the structure after the resist is removed. Advantageously, the high angle ion milling more closely aligns the hard bias materials with a free layer structure in the read sensor structure such that the effectiveness of the hard bias materials is increased.
1. A method for use in forming a read sensor for a magnetic head, comprising:
forming a plurality of read sensor layers over a first shield layer;
forming a resist without undercuts over the plurality of read sensor layers in a central region;
with the resist in place:
milling so that read sensor materials in side regions adjacent the central region are removed to thereby form a read sensor structure in the central region;
depositing insulator materials in the side regions and over the resist;
depositing metallic seed materials over the insulator materials; and
high angle ion milling to reduce a thickness of the metallic seed materials along sidewalls of the read sensor structure.
2. The method of claim 1 , further comprising:
depositing magnetic hard bias materials over the metallic seed materials;
removing the resist; and
depositing a second shield layer over the read sensor structure and the magnetic hard bias materials in the side regions.
3. The method of claim 1 , wherein the read sensor comprises a current-perpendicular-to-the-planes (CPP) read sensor.
4. The method of claim 1 , wherein the first and second shield layers also act as first and second lead layers in a current-perpendicular-to-the-planes (CPP) read sensor.
5. The method of claim 1 , wherein the act of performing high angle ion milling corresponds to angles ranging from 40° to 80°.
6. The method of claim 1 , further comprising:
wherein the plurality of read sensor layers are formed with a free layer structure; and
wherein the metallic seed materials are deposited with a sufficient thickness so as to help position hard bias materials in alignment with the free layer structure.
7. The method of claim 1 , further comprising:
prior to depositing the metallic seed materials, high angle ion milling the insulator materials from the sidewalls of the read sensor structure.
8. The method of claim 1 , further comprising:
wherein the act of high angle ion milling of the metallic seed materials from the sidewalls of the read sensor structure reduces a spacing between hard bias materials and a free layer structure in the read sensor structure.
9. The method of claim 1 , further comprising:
after performing the high angle ion mill, depositing additional metallic seed materials over the milled metallic seed materials.
10. A method for use in forming a read sensor for a magnetic head, comprising:
forming a plurality of read sensor layers over a first shield layer;
forming a resist without undercuts over the plurality of read sensor layers in a central region;
with the resist in place:
milling so that read sensor materials in side regions adjacent the central region are removed to thereby form a read sensor structure in the central region;
depositing insulator materials in the side regions and over the resist; and
high angle ion milling to reduce a thickness of the insulator materials along sidewalls of the read sensor structure.
11. The method of claim 10 , further comprising:
depositing metallic seed materials over the insulator materials; and
depositing magnetic hard bias materials over the metallic seed materials.
12. The method of claim 10 , further comprising:
depositing metallic seed materials over the insulator materials;
high angle ion milling to reduce a thickness of the metallic seed materials along sidewalls of the read sensor structure; and
depositing magnetic hard bias materials over the metallic seed materials.
13. The method of claim 10 , further comprising:
depositing metallic seed materials over the insulator materials;
high angle ion milling to reduce a thickness of the metallic seed materials along sidewalls of the read sensor structure;
depositing magnetic hard bias materials over the metallic seed materials;
removing the resist; and
depositing a second shield layer over the read sensor structure and the magnetic hard bias materials in the side regions.
14. The method of claim 10 , wherein the read sensor comprises a current-perpendicular-to-the-planes (CPP) read sensor.
15. The method of claim 10 , wherein the first and second shield layers also act as first and second lead layers in a current-perpendicular-to-the-planes (CPP) read sensor.
16. The method of claim 10 , wherein the act of performing high angle ion milling corresponds to angles ranging from 40° to 80°.
17. The method of claim 10 , further comprising:
wherein the plurality of read sensor layers are formed with a free layer structure; and
wherein the insulator materials are deposited with a sufficient thickness so as to help position hard bias materials in alignment with the free layer structure.
18. The method of claim 10 , further comprising:
wherein the act of high angle ion milling the insulator materials from the sidewalls of the read sensor structure helps reduce a distance between edges of hard bias materials and a free layer structure of the read sensor structure.
19. The method of claim 10 , further comprising:
depositing metallic seed materials over the insulator materials;
high angle ion milling to reduce a thickness of the metallic seed materials along sidewalls of the read sensor structure;
depositing magnetic hard bias materials over the metallic seed materials; and
wherein the act of high angle ion milling of the metallic seed materials from the sidewalls of the read sensor structure reduces a distance between the magnetic hard bias materials and a free layer structure of the read sensor structure.
20. A method for use in forming a read sensor for a magnetic head, comprising:
forming a plurality of read sensor layers directly over a first shield layer;
forming a resist without undercuts over the plurality of read sensor layers in a central region;
with the resist in place:
milling so that read sensor materials in side regions adjacent the central region are removed to thereby form a read sensor structure in the central region;
depositing insulator materials in the side regions and over the resist;
high angle ion milling to reduce a thickness of the insulator materials along sidewalls of the read sensor structure;
depositing metallic seed materials over the insulator materials;
high angle ion milling to reduce a thickness of the metallic seed materials along sidewalls of the read sensor structure;
depositing magnetic hard bias materials over the metallic seed materials;
removing the resist; and
depositing a second shield layer over the read sensor structure and the hard bias materials in the side regions.
21. The method of claim 20 , wherein the read sensor comprises a current-perpendicular-to the-planes (CPP) read sensor.
22. The method of claim 20 , wherein the first and second shield layer materials comprise one of nickel-iron (Ni—Fe) and cobalt-iron (Co—Fe).
23. The method of claim 20 , wherein the first and second shield layers also act as first and second lead layers in a current-perpendicular-to-the-planes (CPP) read sensor.
24. The method of claim 20 , wherein the insulator material comprises alumina (Al 2 O 3 ).
25. The method of claim 20 , wherein the metallic seed material comprises chromium (Cr).
26. The method of claim 20 , wherein the act of performing high angle ion milling corresponds to angles ranging from 40° to 80°.
27. The method of claim 20 , wherein the magnetic hard bias materials comprise cobalt-platinum-chromium (Co—Pt—Cr).
28. The method of claim 20 , further comprising:
wherein the plurality of read sensor layers are formed with a free layer structure; and
wherein the insulator materials are deposited with a sufficient thickness so as to help position the magnetic hard bias materials in alignment with the free layer structure.
29. The method of claim 20 , further comprising:
wherein the act of high angle ion milling the insulator materials from the sidewalls of the read sensor structure helps reduce a distance between edges of the hard bias materials and a free layer structure of the read sensor structure.
30. The method of claim 20 , further comprising:
prior to depositing the magnetic hard bias materials, forming additional metallic seed materials over the milled metallic seed materials.