Current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) sensor having a top shield with an antiparallel structure
US8638530B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 2013 |
| Grant date | Jan 28, 2014 |
| Priority date | — |
| Expiry date | Feb 20, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/3996
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A current-perpendicular-to-the-plane magnetoresistive sensor structure includes at least an improved top shield structure and optionally also a similar bottom shield structure. The top shield structure includes an antiparallel structure (APS) of two ferromagnetic films and a nonmagnetic antiparallel coupling (APC) film between them. The APC film induces antiferromagnetic (AF) coupling between the two ferromagnetic films so that they have their respective magnetizations oriented antiparallel. An important aspect of the APS is that there is no antiferromagnetic layer adjacent the upper ferromagnetic film, so that the upper ferromagnetic film does not have its magnetization pinned by an antiferromagnetic layer. An electroplated shield layer is formed above the APS. A nonmagnetic decoupling layer is located between the APS and the electroplated shield layer to prevent domain wall movement in the electroplated shield from transferring to the ferromagnetic layers in the APS and thus possibly induce noise in the sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.