Capping structure for enhancing dR/R of the MTJ device
US7449345B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jun 15, 2004 |
| Grant date | Nov 11, 2008 |
| Priority date | — |
| Expiry date | Dec 29, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N50/85
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An MTJ in an MRAM array or in a TMR read head is comprised of a capping layer with a lower inter-diffusion barrier layer, an intermediate oxygen gettering layer, and an upper metal layer that contacts a top conductor. The composite capping layer is especially useful with a moderate spin polarization free layer such as a NiFe layer with a Fe content of about 17.5 to 20 atomic %. The capping layer preferably has a Ru/Ta/Ru configuration in which the lower Ru layer is about 10 to 30 Angstroms thick and the Ta layer is about 30 Angstroms thick. As a result, a high dR/R of about 40% is achieved with low magnetostriction less than about 1.0 E−6 in an MTJ in an MRAM array. Best results are obtained with an AlOx tunnel barrier layer formed by an in-situ ROX process on an 8 to 10 Angstrom thick Al layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.