High thermal stability free layer with high out-of-plane anisotropy for magnetic device applications
US8946834B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 1, 2012 |
| Grant date | Feb 3, 2015 |
| Priority date | — |
| Expiry date | Mar 1, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1143
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A CoFeB or CoFeNiB magnetic layer wherein the boron content is 25 to 40 atomic % and with a thickness <20 Angstroms is used to achieve high perpendicular magnetic anisotropy and enhanced thermal stability in magnetic devices. A dusting layer made of Co, Ni, Fe or alloy thereof is added to top and bottom surfaces of the CoFeB layer to increase magnetoresistance as well as improve Hc and Hk. Another embodiment includes a non-magnetic metal insertion in the CoFeB free layer. The CoFeB layer with elevated B content may be incorporated as a free layer, dipole layer, or reference layer in STT-MRAM memory elements or in spintronic devices including a spin transfer oscillator. Thermal stability is increased such that substantial Hk is retained after annealing to at least 400° C. for 1 hour. 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.