Magnetic tunnel junction memory cell with in-stack biasing of the free ferromagnetic layer and memory array using the cell
US6114719A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 1998 |
| Grant date | Sep 5, 2000 |
| Priority date | — |
| Expiry date | May 29, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B61/10
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A magnetic tunnel junction (MTJ) memory cell uses a biasing ferromagnetic layer in the MTJ stack of layers that is magnetostatically coupled with the free ferromagnetic layer in the MTJ stack to provide transverse and/or longitudinal bias fields to the free ferromagnetic layer. The MTJ is formed on an electrical lead on a substrate and is made up of a stack of layers. The layers in the MTJ 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 free 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, and whose moment, in the absence of any applied field, is generally either parallel or antiparallel to that of the fixed ferromagnetic layer, a biasing ferromagnetic layer that has its magnetic moment aligned generally in the plane of the MTJ, and a nonferromagnetic electrically conductive spacer layer separating the biasing ferromagnetic layer from the other la…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.