Magnetic tunnel junction device with antiferromagnetically coupled pinned layer
US5841692A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 1997 |
| Grant date | Nov 24, 1998 |
| Priority date | — |
| Expiry date | Jul 16, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/3996
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetic tunnel junction (MTJ) device is usable as a magnetic field sensor or as a memory cell in a magnetic random access (MRAM) array. The MTJ device has a "pinned" ferromagnetic layer whose magnetization is oriented in the plane of the layer but is fixed so as to not be able to rotate in the presence of an applied magnetic field in the range of interest, a "free" ferromagnetic layer whose magnetization is able to be rotated in the plane of the layer relative to the fixed magnetization of the pinned ferromagnetic layer, and an insulating tunnel barrier layer located between and in contact with both ferromagnetic layers. The pinned ferromagnetic layer is formed as a sandwich of two antiferromagnetically coupled ferromagnetic layers separated by a metallic layer. The free and pinned ferromagnetic layers are located in separate spaced-apart planes so as to not overlap the tunnel barrier layer. An insulating layer surrounds the lateral perimeter of at least the free ferromagnetic layer and supports an electrical lead that makes contact with the free ferromagnetic layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.