Process of forming a recessed spin flipping element in the write gap

A process of forming a spin torque assisted magnetic recording writer, comprising:

• (a) providing a main pole (MP) comprised of a MP tip having a tapered trailing side bounded by two sides that each extend from an air bearing surface (ABS) plane to a MP corner at a first height (a) where the MP tapered trailing side connects to a top surface of a MP back portion and the MP corners are separated by a first cross-track width (w1), wherein the MP top surface is aligned orthogonal to the ABS plane, and the MP tapered trailing side is coplanar with a tapered front side of a dielectric layer on the MP top surface;
• (b) depositing a spin torque oscillator (STO) stack of layers with a thickness (t) on the MP tapered trailing side and on the dielectric layer, the STO stack of layers comprises:
• (1) a lower non-spin preserving layer;
• (2) a middle flux guiding layer (FGL) having a magnetization aligned parallel to a write gap field from the MP during a write process, and wherein the spin torque assisted magnetic recording writer is configured so that the FGL magnetization flips to an opposite direction when a current Ib of sufficient magnitude is applied in a direction from a first trailing shield (TS) towards the MP tapered trailing side;
• and
• (3) an upper spin preserving layer;
• (c) forming a pattern in the STO stack of layers wherein a resulting STO shape having two sides separated with a constant second cross-track width (w), or separated with increasing or decreasing width with increasing distance from the ABS plane;
• (d) forming a STO front side at a second height (b), and a STO backside at a third height (h+b) from the STO front side, and wherein the STO front side and backside are connected by the two STO sides thereby defining a STO device having a height h;
• (e) depositing a write gap with a second thickness (d1) on the MP tapered trailing side between the ABS plane and the STO front side, and adjoining the STO backside, and adjoining the two STO sides;
• (f) depositing the first TS layer on the write gap and on the STO device, and forming two sides on the first TS layer and write gap that are separated by a third cross-track width (w2) at the ABS plane, wherein the two sides extend in a down-track direction to a top surface of a side shield on each side of the MP tip, and wherein w2>a maximum width of the STO device;
• and
• (g) depositing a second TS layer on the first TS layer and on the top surface of each side shield, and then simultaneously forming a backside on the first and second TS layers at a fourth height (s) from the ABS plane.