Magnetic memory
US8957486B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 4, 2009 |
| Grant date | Feb 17, 2015 |
| Priority date | — |
| Expiry date | May 6, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C11/1675
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Provided is a magnetic random access memory to which spin torque magnetization reversal is applied, the magnetic random access memory being thermal stable in a reading operation and also being capable of reducing a current in a wiring operation. A magnetoresistive effect element formed by sequentially stacking a fixed layer, a nonmagnetic barrier layer, and a recording layer is used as a memory element. The recording layer adopts a laminated ferrimagnetic structure. The magnetic memory satisfies the expression Ms2(t/w)>|Jex|>(2kBTΔ)/S, in which kB is a Boltzmann constant, T is an operating temperature of the magnetic memory, S is an area parallel to a film surface of the magnetoresistive effect element, t and Ms are respectively a film thickness and a saturated magnetization of the ferromagnetic layer having a smaller film thickness among two ferromagnetic layers which are constituent members of the laminated ferrimagnetic structure, w is a length of a short side of the recording layer, Δ is a thermal stability index of the magnetic memory, and Jex is exchange coupling energy acting between the two ferromagnetic layers of the recording layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.