Current perpendicular to the planes (CPP) sensor with a highly conductive cap structure
View Patent ↗A magnetic read head has a current perpendicular to the planes (CPP) sensor with a top cap layer that is ruthenium (Ru) or rhodium (Rh) or a top cap layer structure which includes a first layer of tantulum (Ta) only, a second layer of ruthenium (Ru), rhodium (Rh) or gold (Au) with the first layer being located between a spacer layer and the second layer.
1. A magnetic read head comprising:
a current perpendicular to the planes (CPP) sensor;
the CPP sensor having a top cap layer structure;
the cap layer structure being composed of a first layer of tantalum (Ta) and a second layer of ruthenium (Ru); and the first layer interfacing the second layer and being located between a spacer layer and the second layer.
2. A magnetic read head as claimed in claim 1 wherein the CPP sensor further comprises:
a ferromagnetic pinned layer structure;
a ferromagnetic free layer structure;
the nonmagnetic spacer layer being located between the pinned layer and the free layer structure.
3. A magnetic read head as claimed in claim 2 further comprising:
ferromagnetic first and second shield layers;
the CPP sensor being located between the first and second shield layers; and
the first and second shield layers serving as first and second leads for conducting a current through the CPP sensor in a direction perpendicular to major thin film planes of the CPP sensor.
4. A magnetic read head as claimed in claim 3 wherein the free layer structure is located between the spacer layer and the cap layer structure.
5. A magnetic read head as claimed in claim 3 wherein the pinned layer structure is located between the spacer layer and the cap layer structure.
6. A magnetic head assembly comprising:
a write head;
a read head adjacent the write head;
the read head comprising:
a current perpendicular to the planes (CPP) sensor;
the CPP sensor having a top cap layer structure;
the cap layer structure being composed of a first layer of tantalum (Ta) and a second layer of ruthenium (Ru); and the first layer interfacing the second layer and being located between a spacer layer and the second layer.
7. A magnetic head assembly as claimed in claim 6 wherein the CPP sensor further comprises:
a ferromagnetic pinned layer structure;
a ferromagnetic free layer structure;
the nonmagnetic spacer being located between the pinned layer structure and the free layer structure.
8. A magnetic head assembly as claimed in claim 7 further comprising:
ferromagnetic first and second shield layers;
the CPP sensor being located between the first and second shield layers; and
the first and second shield layers serving as first and second leads for conducting a current through the CPP sensor in a direction perpendicular to major thin film planes of the CPP sensor.
9. A magnetic disk drive comprising:
at least one magnetic head assembly that has a head surface;
the magnetic head assembly having a write head and a read head;
the read head including:
a current perpendicular to the planes (CPP) sensor;
the CPP sensor having a top cap layer structure;
the cap layer structure being composed of a first layer of tantalum (Ta) and a second layer of ruthenium (Ru); and the first layer interfacing the second layer and being located between a spacer layer and the second layer
ferromagnetic first and second shield layers; and the CPP sensor being located between the first and second shield layers;
a housing;
a magnetic medium supported in the housing;
a support mounted in the housing for supporting the magnetic head assembly with said head surface facing the magnetic medium so that the magnetic head assembly is in a transducing relationship with the magnetic medium;
a motor for moving the magnetic medium; and
a processor connected to the magnetic head assembly and to the motor for exchanging signals with the magnetic head assembly and for controlling movement of the magnetic medium.
10. A magnetic disk drive as claimed in claim 9 wherein the CPP sensor further comprises:
a ferromagnetic pinned layer structure;
a ferromagnetic free layer structure;
the nonmagnetic spacer layer being located between the pinned layer structure and the free layer structure.
11. A magnetic read head comprising:
a current perpendicular to the planes (CPP) sensor;
the CPP sensor having a top cap layer structure which includes:
a first layer of tantalum (Ta) only;
a second layer of rhodium (Rh); and
the first layer interfacing the second layer and being located between a spacer layer and the second layer.
12. A magnetic read head as claimed in claim 11 wherein the CPP sensor further comprises:
a ferromagnetic pinned layer structure;
a ferromagnetic free layer structure; and
the spacer layer being located between the pinned layer structure and the free layer structure.
13. A magnetic read head as claimed in claim 12 further comprising:
ferromagnetic first and second shield layers;
the CPP sensor being located between the first and second shield layers; and
the first and second shield layers serving as first and second leads for conducting a current through the CPP sensor in a direction perpendicular to major thin film planes of the CPP sensor.
14. A magnetic read head as claimed in claim 12 wherein the first layer also interfaces the free layer structure.
15. A magnetic read head as claimed in claim 12 wherein the first layer also interfaces the pinned layer structure.