Free layer structure in magnetic random access memory (MRAM) for Mo or W perpendicular magnetic anisotropy (PMA) enhancing layer
US11087810B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 2020 |
| Grant date | Aug 10, 2021 |
| Priority date | — |
| Expiry date | Apr 9, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N50/85
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A perpendicularly magnetized magnetic tunnel junction (p-MTJ) is disclosed wherein a free layer (FL) has a first interface with a MgO tunnel barrier, a second interface with a Mo or W Hk enhancing layer, and is comprised of FexCoyBz wherein x is 66-80, y is 5-9, z is 15-28, and (x+y+z)=100 to simultaneously provide a magnetoresistive ratio >100%, resistance x area product <5 ohm/□m2, switching voltage <0.15 V (direct current), and sufficient Hk to ensure thermal stability to 400° C. annealing. The FL may further comprise one or more M elements such as O or N to give (FexCoyBz)wM100-w where w is >90 atomic %. Alternatively, the FL is a trilayer with a FeB layer contacting MgO to induce Hk at the first interface, a middle FeCoB layer for enhanced magnetoresistive ratio, and a Fe or FeB layer adjoining the Hk enhancing layer to increase thermal stability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.