Magnetic recording write head with spin-torque oscillator (STO) and extended seed layer

A microwave-assisted magnetic recording (MAMR) assembly comprising:

• at least one load beam assembly;
• a flexure coupled to the at least one load beam assembly;
• a slider coupled to the flexure, the slider having a trailing surface;
• a write head coupled to the trailing surface of the slider, the write head comprising:
• a write pole having a first cross-track width;
• an insulating material surrounding at least two sides of the write pole;
• a substrate surrounding at least two sides of the insulating material, wherein the write pole and the insulating material are recessed into the substrate, and wherein a surface of the write pole, a surface of the substrate, and a surface of the insulating material align to form a substantially planar surface;
• a seed layer disposed on the write pole and a portion of the insulating material on the substantially planar surface, the seed layer having a second cross-track width greater than the first cross-track width;
• a spin torque oscillator disposed on the seed layer, the spin torque oscillator having a third cross-track width less than both the first cross-track width of the write pole and the second cross-track width of the seed layer;
• a capping layer disposed on the spin torque oscillator;
• a diamond-like carbon hard mask layer disposed on the capping layer;
• a polyimide coating disposed on the diamond-like carbon hard mask layer;
• a silicon hard mask disposed on the polyimide coating;
• and
• one or more insulating refill layers disposed on the substantially planar surface adjacent to the seed layer and the spin torque oscillator, wherein the one or more insulating refill layers comprise a first insulating refill layer and a second insulating refill layer, wherein the first insulating refill layer contacts the seed layer, the spin torque oscillator, the capping layer, the diamond-like carbon hard mask layer, the polyimide coating, and the silicon hard mask.

A write head, comprising:

• a substrate;
• a write pole recessed into the substrate;
• an insulating material surrounding at least two sides of the write pole, the insulating material recessed into the substrate, wherein a surface of the write pole, a surface of the substrate, and a surface of the insulating material align to form a substantially planar surface;
• a seed layer disposed at a gas bearing surface (GBS) on the write pole and a portion of the insulating material on the substantially planar surface, the seed layer having a first cross-track width parallel to the substantially planar surface of the substrate and a first depth in a direction orthogonal to the GBS;
• a spin torque oscillator disposed at the GBS on the seed layer, the spin torque oscillator having a second cross-track width less than the first cross-track width of the seed layer and a second depth in the direction orthogonal to the GBS less than the first depth;
• and
• a first insulating refill layer disposed on the substantially planar surface adjacent to the seed layer and the spin torque oscillator;
• and
• a second insulating refill layer disposed on the first insulating refill layer, the second insulating refill layer being disposed over at least a portion of the seed layer in an along-a-track direction.