Thermally-assisted magnetic recording head having symmetric optical side shields

Patent metadata

Field	Value
Publication number	US-10068596-B2
Application number	US-201615285721-A
Country	US
Kind code	B2
Filing date	Oct 5, 2016
Priority date	Oct 5, 2016
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

An optically shielded TAMR (thermally assisted magnetic recording) write head has a metal waveguide blocker formed against a distal end of a waveguide and a pair of symmetrically disposed optical side shields formed to either side of a plasmon generator formed above the waveguide. The waveguide focuses optical radiation on the adjacent plasmon generator where it excites plasmon modes that heat the recording medium with near-field energy and the waveguide blocker prevents excess optical radiation from blurring the spot on the recording region. The optical side shields further restrict loosely coupled optical radiation from reaching the recording region and blurring the optical spot and improves down-track and cross-track thermal gradients.

First claim

What is claimed is:

1. An optically shielded TAMR (Thermally Assisted Magnetic Recording) write head comprising:
a magnetic writer having a main write pole emerging at a distal ABS (air-bearing surface);
write pole heat sink layers symmetrically disposed to either side of said main write pole;
a waveguide formed adjacent to said main write pole configured for directing electromagnetic radiation at a plasmon generator;
said plasmon generator formed adjacent to said waveguide and positioned beneath said main pole, wherein said plasmon generator is electromagnetically coupled to said waveguide at a distal end of said waveguide, whereby plasmon modes are excited within said plasmon generator, said modes having near-field energy that said plasmon generator is configured to direct at a confined region of a recording medium immediately adjacent to said ABS of said main write pole, within which confined region said near fields produce Joule heating of said recording medium;
a scalable, metallic peg emerging distally from said plasmon generator and configured to further concentrate said near-field plasmon energy within said confined region of said recording medium; and
a system configured for shielding said recording medium from portions of said electromagnetically coupled optical radiation that are only loosely coupled and may impinge on said recording medium and its surroundings while said write head is operational, said system further comprising:
a waveguide blocker conformally abutting against said distal end of said waveguide, wherein said waveguide blocker is configured to prevent said loosely coupled radiative energy from said waveguide from being transferred to said confined region of said recording medium and its surroundings; and
optical side shields formed of optically opaque material laterally disposed adjacent to and substantially symmetrically opposing said plasmon generator, wherein said optical side shields are configured to further prevent loosely coupled radiative energy from said waveguide from being transferred to said recording medium and its surroundings: wherein
said optical side shields are triangular prisms or trapezoidal prisms or irregular prisms, said prisms having a first face that is coplanar with said ABS plane and a second face that extends rearward from said first face and makes an angle with a symmetry plane that provides a clearance between said second face and a periphery of said plasmon generator.

2. The TAMR write head of claim 1 wherein both said optical side shields and said waveguide blocker are formed of Ru.

3. The TAMR write head of claim 1 wherein said first face is L-shaped, with a vertical portion extending vertically downward from said main pole heat sink layer to contact said waveguide blocker and a horizontal portion extending horizontally outward from said vertical portion and having a lower edge that is conformal to an upper edge of said waveguide blocker.

4. The TAMR write head of claim 1 wherein said first face has an angular L-shape, with an obtuse angle between the two portions of the L, wherein the vertical portion of the L extends vertically downward from said main pole heat sink layer to contact said waveguide blocker and a horizontal portion extending horizontally outward from said vertical portion and having a lower edge that is conformal to an upper edge of said waveguide blocker.

5. The TAMR write head of claim 4 wherein said L shape has an approximately vertical portion that makes an obtuse angle of between 70° and 90° with a horizontal portion, wherein said approximately vertical portion is of width approximately 64 nm and wherein said horizontal portion is of thickness approximately 45 nm and wherein said side shield extends rearward in a direction away from the periphery of said plasmon generator with an angle of approximately 45°.

6. The TAMR write head of claim 3 wherein said L shape has a vertical portion of width approximately 64 nm and a horizontal portion of thickness approximately 45 nm and that extends rearward in a direction away from the periphery of said plasmon generator with an angle of approximately 45°.

7. The TAMR write head of claim 1 wherein outer edges of said peg are separated from inner edges of said optical side shields by ≤70 nm.

8. The TAMR write head of claim 1 wherein said plasmon generator has a flat parabolic horizontal cross-sectional shape and is aligned symmetrically above said waveguide.

9. The TAMR write head of claim 1 wherein said plasmon generator is formed of Au.

10. The TAMR write head of claim 6 wherein said plasmon generator is formed as a bilayer comprising a layer of Au over a layer of Rh.

11. The TAMR write head of claim 1 wherein said plasmon generator may be aligned symmetrically above or below said waveguide.

12. The TAMR write head of claim 1 wherein said waveguide blocker is formed upon a magnetic return pole which also acts as a leading edge shield.

13. The TAMR write head of claim 1 wherein said waveguide blocker is formed upon a magnetic return pole which also acts as a leading edge shield and a heat sink layer.

14. The TAMR write head of claim 1 wherein said waveguide blocker is formed upon a heat sink layer.

15. A method for forming an optically shielded TAMR head, comprising:
providing a magnetic write head having a main write pole with write pole side shields horizontally symmetrically disposed about said write pole; and a heat sink layer formed on a leading edge side of said main write pole; then
forming a layered structure beneath said main write pole wherein said layered structure includes a plasmon generator (PG) including a peg layer having a scalable peg configured to concentrate plasmon near-field energy within a confined region on a magnetic recording medium; wherein said layered structure further includes
a waveguide layer formed beneath said PG, wherein said waveguide layer will be configured to couple optical radiation to plasmon modes in said PG and wherein said waveguide has a waveguide blocker formed against a distal end and wherein said waveguide blocker contacts said heat sink layer; then
planarizing said peg layer of said layered structure using chemical mechanical polishing (CMP) and
forming a pair of optically opaque side shields on said planarized layered structure wherein said optically opaque side shields are substantially symmetrically disposed about said PPG, and wherein said side shields will further define said waveguide shape and wherein said optically opaque side shields are configured to block loosely coupled optical radiation from impinging on said confined region.

16. The method of claim 15 wherein said pair of optically opaque side shields are formed by a method further comprising:
depositing on said planarized peg layer of said layered structure a sequence of additional layers including, in the following order:
a first atomic layer deposition of Al 2 O 3 (ALD Al 2 O 3 ) as a protective layer on said peg layer;
a layer of SiO 2 on said first ALD Al 2 O 3 layer;
a second ALD Al 2 O 3 protective layer on said oxide layer; and
a metal mask (MM) layer on said second ALD Al 2 O 3 layer, wherein said metal mask layer will be patterned to define said optically opaque side shields.

17. The method of claim 16 wherein said optical side shields are patterned by a method further comprising:
depositing a bilayer coating of photoresist (PR) on said MM layer and patterning said bilayer coating with said optical side shield feature; then
transferring said pattern to said MM layer using an ion beam etch (IBE); then str

Assignees

• Headway Tech Inc

Inventors

• Staffaroni Matteo
• Maletzky Tobias
• Jin Xuhui
• Xu Weihao
• Takano Kenichi

Classifications

• G11B5/3169

  Working or finishing the interfacing surface of heads, e.g. lapping of heads · CPC title

• G11B5/3143

  including additional layers for improving the electromagnetic transducing properties of the basic structure, e.g. for flux coupling, guiding or shielding (G11B5/3116, G11B5/312 take precedence) · CPC title

• G11B7/22

  Apparatus or processes for the manufacture of optical heads, e.g. assembly · CPC title

• G11B5/3133

  including layers not usually being a part of the electromagnetic transducer structure and providing additional features, e.g. for improving heat radiation, reduction of power dissipation, adaptations for measurement or indication of gap depth or other properties of the structure (G11B5/3106 takes precedence) · CPC title

• G11B5/6088

  Optical waveguide in or on flying head · CPC title