DFL read head with SiOx cap layer on AlOx refill layers

A read head, comprising:

• a dual free layer (DFL) sensor having a first surface disposed at a media facing surface (MFS), a second surface opposite the first surface, a third surface adjacent to the first surface, a fourth surface opposite the third surface, a top surface, and a bottom surface opposite the top surface, wherein the read head further comprises a first soft bias side shield disposed adjacent to the third surface and a second soft bias side shield disposed adjacent to the fourth surface;
• a rear hard bias (RHB) structure having a first surface disposed adjacent to the second surface of the DFL sensor, a second surface opposite the first surface, a third surface aligned with the third surface of the DFL sensor, a fourth surface aligned with the fourth surface of the DFL sensor, a top surface, and a bottom surface opposite the top surface;
• a nonmagnetic layer disposed on the top surface of the RHB structure;
• an insulating layer disposed around the second, third, and fourth surfaces of the RHB structure, and around the third and fourth surfaces of the DFL sensor;
• and
• a SiOx cap layer disposed on the insulating layer, where x is an integer greater than or equal to 1, the SiOx cap layer being disposed adjacent to the top surface of the DFL sensor and the top surface of the RHB structure, and extending to the MFS.

A read head, comprising:

• a dual free layer (DFL) sensor having a first surface disposed at a media facing surface (MFS), a second surface opposite the first surface, a third surface adjacent to the first surface, and a fourth surface opposite the third surface, the read head further comprising a first soft bias side shield disposed adjacent to the third surface and a second soft bias side shield disposed adjacent to the fourth surface;
• a rear hard bias (RHB) structure having a first surface disposed adjacent to the second surface of the DFL sensor;
• a nonmagnetic layer disposed on the RHB structure;
• an insulating layer disposed around an outer perimeter of the RHB structure and the third and fourth surfaces of the DFL sensor;
• and
• a SiOx cap layer disposed on the insulating layer, where x is an integer greater than or equal to 1, the SiOx cap layer being disposed around the outer perimeter of the RHB structure and the third and fourth surfaces of the DFL sensor, and extending to the MFS.