Current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) sensor structure with multiple stacked sensors and center shield with CoFeB insertion layer
US8873204B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 2014 |
| Grant date | Oct 28, 2014 |
| Priority date | — |
| Expiry date | Jul 25, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/3912
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A two-dimensional magnetic recording (TDMR) read head structure has the lower read sensor free layer magnetization biased by side shields of soft magnetic material. A center shield between the lower and upper sensors is an antiparallel coupled magnetic structure, i.e., first and second ferromagnetic layers separated by an antiparallel coupling (APC) layer. The first ferromagnetic layer is ferromagnetically exchange coupled to the side shields of the lower sensor to stabilize the magnetization of the lower sensor's free layer. The first ferromagnetic layer of the center shield is a multilayer of a lower NiFe layer and an upper CoFeB alloy layer inserted below the APC layer. The CoFeB alloy insertion layer increases the antiparallel coupling of the first and second ferromagnetic layers of the center shield after two orthogonal anneals so that the magnetization of the first ferromagnetic layer is aligned parallel to the air-bearing surface (ABS) of the TDMR structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.