High performance MTJ element for STT-RAM and method for making the same
US8080432B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 2010 |
| Grant date | Dec 20, 2011 |
| Priority date | — |
| Expiry date | Jun 21, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F10/3295
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of forming a STT-MTJ MRAM cell that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes an IrMn pinning layer, a SyAP pinned layer, a naturally oxidized, crystalline MgO tunneling barrier layer that is formed on an Ar-ion plasma smoothed surface of the pinned layer and, in one embodiment, a free layer that comprises an amorphous layer of Co60Fe20B20. of approximately 20 angstroms thickness formed between two crystalline layers of Fe of 3 and 6 angstroms thickness respectively. The free layer is characterized by a low Gilbert damping factor and by very strong polarizing action on conduction electrons. The resulting cell has a low critical current, a high dR/R and a plurality of such cells will exhibit a low variation of both resistance and pinned layer magnetization angular dispersion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.