Minimal thickness synthetic antiferromagnetic (SAF) structure with perpendicular magnetic anisotropy for STT-MRAM
US8860156B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 2012 |
| Grant date | Oct 14, 2014 |
| Priority date | — |
| Expiry date | Sep 24, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F10/3286
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A synthetic antiferromagnetic (SAF) structure for a spintronic device is disclosed and has an AP2/antiferromagnetic (AF) coupling/CoFeB configuration. The SAF structure is thinned to reduce the fringing (Ho) field while maintaining high coercivity. The AP2 reference layer has intrinsic perpendicular magnetic anisotropy (PMA) and induces PMA in a thin CoFeB layer through AF coupling. In one embodiment, AF coupling is improved by inserting a Co dusting layer on top and bottom surfaces of a Ru AF coupling layer. When AP2 is (Co/Ni)4, and CoFeB thickness is 7.5 Angstroms, Ho is reduced to 125 Oe, Hc is 1000 Oe, and a balanced saturation magnetization-thickness product (Mst)=0.99 is achieved. The SAF structure may also be represented as FL2/AF coupling/CoFeB where FL2 is a ferromagnetic layer with intrinsic PMA.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.