Magnetic tunnel junction magnetoresistive sensor with in-stack biasing
US6023395A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 1998 |
| Grant date | Feb 8, 2000 |
| Priority date | — |
| Expiry date | May 29, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/3996
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetic tunnel junction (MTJ) magnetoresistive (MR) read head has one fixed ferromagnetic layer and one sensing ferromagnetic layer on opposite sides of the tunnel barrier layer, and with a biasing ferromagnetic layer in the MTJ stack of layers that is magnetostatically coupled with the sensing ferromagnetic layer to provide either longitudinal bias or transverse bias or a combination of longitudinal and transverse bias fields to the sensing ferromagnetic layer. The magnetic tunnel junction in the MTJ MR head is formed on an electrical lead on a substrate and is made up of a stack of layers. The layers in the stack are an antiferromagnetic layer, a fixed ferromagnetic layer exchange biased with the antiferromagnetic layer so that its magnetic moment cannot rotate in the presence of an applied magnetic field, an insulating tunnel barrier layer in contact with the fixed ferromagnetic layer, a sensing ferromagnetic layer in contact with the tunnel barrier layer and whose magnetic moment is free to rotate in the presence of an applied magnetic field, a biasing ferromagnetic layer that has its magnetic moment aligned generally within the plane of the device and a nonmagnetic electric…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.