Microwave-assisted magnetic recording head having a current confinement structure

1. A high-frequency magnetic field-assisted magnetic recording head, comprising:

a main pole adapted for producing a writing magnetic field;

a spin torque oscillator (STO) positioned above the main pole;

a low-resistance layer positioned above the STO; and

a current confinement layer positioned between the low-resistance layer and the main pole,

wherein the main pole and the low-resistance layer are adapted for acting as poles for writing data to a magnetic medium in response to a flow of current to the STO positioned therebetween to generate a high-frequency magnetic field which overlaps with the writing magnetic field, and

wherein the current confinement layer is adapted for controlling a current density and/or a current density distribution of the current flowing to the STO.

2. The head as recited in claim 1 , further comprising a trailing shield that comprises the low-resistance layer, the trailing shield being positioned on a trailing side of the main pole.

3. The head as recited in claim 2 , wherein the current confinement layer is positioned between the STO and the trailing shield, and wherein an aperture in the current confinement layer allows the STO and the trailing shield to be in contact with one another.

4. The head as recited in claim 3 , wherein a width of the aperture provided in the current confinement layer in a track-width direction is narrower than a width of the STO in the track-width direction.

5. The head as recited in claim 4 , wherein a width of the main pole in a track-width direction is at least as great as the width of the aperture provided in the current confinement layer in the track-width direction.

6. The head as recited in claim 1 , wherein a height of the current confinement layer from the media-facing surface thereof is less than a height of the trailing shield from the media-facing surface thereof.

7. The head as recited in claim 1 , wherein the current confinement layer is positioned between the main pole and the STO.

8. The head as recited in claim 7 , further comprising a second current confinement layer positioned between the low-resistance layer and the STO.

9. The head as recited in claim 1 , wherein the current confinement layer is positioned between the low-resistance layer and the STO.

10. The head as recited in claim 1 , wherein a width of the STO in a track-width direction near a media-facing surface thereof is greater than a width of the main pole in the track-width direction near a media-facing surface thereof.

11. The head as recited in claim 1 , wherein a width of the main pole in a track-width direction near a media-facing surface thereof is at least as great as a width of a current conductive region of the current confinement layer in the track-width direction near a media-facing surface thereof.

12. A magnetic data storage system, comprising:

at least one head as recited in claim 1 ;

a magnetic medium;

a drive mechanism for passing the magnetic medium over the at least one head; and

a controller electrically coupled to the at least one head for controlling operation of the at least one head.

13. A method, comprising:

forming a main pole;

forming a current confinement layer above the main pole;

forming a spin torque oscillator (STO) above the current confinement layer; and

forming a low-resistance layer above the STO in order to form the head as recited in claim 1 .

14. The method as recited in claim 13 , further comprising forming a second current confinement layer positioned above the STO.

15. A method, comprising:

forming a main pole;

forming a spin torque oscillator (STO) above the main pole;

forming a current confinement layer above the STO; and

forming a low-resistance layer above the current confinement layer in order to form the head as recited in claim 1 .

16. A microwave-assisted magnetic recording (MAMR) head, comprising:

a main pole adapted for producing a writing magnetic field;

a spin torque oscillator (STO) positioned above the main pole;

a trailing shield positioned above the STO, wherein the trailing shield comprises a low-resistance layer; and

a current confinement layer positioned between the trailing shield and the main pole,

wherein the main pole and the low-resistance layer of the trailing shield are adapted for acting as poles for writing data to a magnetic medium in response to a flow of current to the STO positioned therebetween to generate a high-frequency magnetic field which overlaps with the writing magnetic field, and

wherein the current confinement layer is adapted for controlling a current density and/or a current density distribution of the current flowing to the STO.

17. The MAMR head as recited in claim 16 , wherein the current confinement layer is positioned between the STO and the trailing shield, and wherein an aperture in the current confinement layer allows the STO and the trailing shield to be in contact with one another.

18. The MAMR head as recited in claim 17 , wherein a width of the aperture provided in the current confinement layer in a track-width direction is narrower than a width of the STO in the track-width direction.

19. The MAMR head as recited in claim 17 , wherein a width of the main pole in a track-width direction is at least as great as the width of the aperture provided in the current confinement layer in the track-width direction.

20. The MAMR head as recited in claim 16 , wherein a height of the current confinement layer from the media-facing surface thereof is less than a height of the trailing shield from the media-facing surface thereof.

21. The MAMR head as recited in claim 16 , wherein the current confinement layer is positioned between the main pole and the STO.

22. The MAMR head as recited in claim 16 , wherein a width of the STO in a track-width direction near a media-facing surface thereof is greater than a width of the main pole in the track-width direction near a media-facing surface thereof.