Write element, thermally assisted magnetic head slider, head gimbal assembly, hard disk drive with the same, and manufacturing method thereof

A manufacturing method of a thermally assisted magnetic head slider, the method comprising:

• (a) providing a wafer with a plurality of thermally assisted magnetic head slider elements each of which has a substrate with an air bearing surface, a read element and a write element including a first magnetic pole, a second magnetic pole, coils, a waveguide, and a plasmon unit;
• (b) cutting the wafer into a plurality of row bars;
• (c) lapping surfaces of the row bars so as to obtain a predetermined requirement;
• (d) etching a first recess on a near-field light generating surface of the plasmon unit, in order to space the plasmon unit apart from the air bearing surface a first predetermined distance;
• (e) depositing a protective layer on the near-field light generating surface of the plasmon unit;
• and
• (f) cutting the row bar into a plurality of individual thermally assisted magnetic head slider,
• wherein the recess is filled in with the protective layer including low light absorption material that is different from that of the magnetic poles.