Near-field transducer with Au nano rod

A thermally assisted magnetic recording (TAMR) device, comprising:

• (a) a main pole (MP) that generates a magnetic field to switch one or more bits in a magnetic medium;
• (b) a waveguide (WG) that provides light to a near field transducer (NFT);
• (c) the NFT formed between the WG and MP and that serves as a plasmon generator (PG) by using light from the WG to excite plasmons that generate near field light, which is transmitted to an air bearing surface (ABS) and produces a heating spot on the magnetic medium thereby lowering the magnetic field required to switch the one or more bits;
• the PG comprises:
• (1) a front portion having a rod-like shape with a front side at the ABS and two sides aligned orthogonal to the ABS and separated by a first width, a tapered back side with a bottom end at a first height (RODh) from the ABS that is greater than a height of the top end thereof, the tapered backside forms an angle α with a bottom surface of the PG front portion;
• and
• (2) a back portion having a front side aligned essentially parallel to the front portion backside and separated therefrom with a first dielectric layer having a first thickness, and wherein the PG back portion has two sides separated by increasing width with increasing distance from the first dielectric layer and terminating at a backside that is parallel to the ABS;
• and
• (d) a second dielectric layer formed on the WG and contacting a back section of the PG front portion bottom surface;
• (e) a third dielectric layer on the WG and contacting a bottom surface of the PG back portion;
• and
• (f) a fourth dielectric layer formed between the first dielectric layer and PG front portion at the ABS, and extending to a backside at a second height (h1) where h1<RODh.

A method of fabricating a TAMR device, comprising:

• (a) providing a first dielectric layer on a waveguide;
• (b) depositing a second dielectric layer on the first dielectric layer and forming a backside on the second dielectric layer at a first height (h1) from a first plane;
• (c) depositing a first plasmon generator (PG) layer on the first and second dielectric layers and forming a tapered backside on the first PG layer that has a bottom end at a second height (RODh) that is greater than a height of a top end of the tapered backside from the first plane, and where RODh>h1;
• (d) sequentially depositing a third dielectric layer and then a second PG layer on the first PG layer and on the WG behind the tapered backside, and forming a top surface on the second PG layer that is coplanar with a top surface of the first PG layer;
• (e) patterning the first PG layer to form a PG front portion having a rod-like shape between the first plane and third dielectric layer, and the second PG layer to form a PG back portion behind the third dielectric layer, wherein the PG back portion has a substantially triangular shape from a top-down view;
• (f) forming a fourth dielectric layer on the PG front portion, and extending from the first plane to a second height (PPSh) from the first plane;
• (g) depositing a main pole (MP) layer on the fourth dielectric layer;
• and
• (h) performing a lapping process to form an air bearing surface (ABS) at the first plane.