Free layer with high thermal stability for magnetic device applications by insertion of a boron dusting layer
US8852760B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 2012 |
| Grant date | Oct 7, 2014 |
| Priority date | — |
| Expiry date | Jul 23, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1143
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A boron or boron containing dusting layer such as CoB or FeB is formed along one or both of top and bottom surfaces of a free layer at interfaces with a tunnel barrier layer and capping layer to improve thermal stability while maintaining other magnetic properties of a MTJ stack. Each dusting layer has a thickness from 0.2 to 20 Angstroms and may be used as deposited, or at temperatures up to 400° C. or higher, or following a subsequent anneal at 400° C. or higher. The free layer may be a single layer of CoFe, Co, CoFeB or CoFeNiB, or may include a non-magnetic insertion layer. The resulting MTJ is suitable for STT-MRAM memory elements or spintronic devices. Perpendicular magnetic anisotropy is maintained in the free layer at temperatures up to 400° C. or higher. Ku enhancement is achieved and the retention time of a memory cell for STT-MRAM designs is increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.