Magnetic tunnel junction with low defect rate after high temperature anneal for magnetic device applications
US9842988B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 2015 |
| Grant date | Dec 12, 2017 |
| Priority date | — |
| Expiry date | Jul 20, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F10/329
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A magnetic tunnel junction is disclosed wherein the reference layer and free layer each comprise one layer having a boron content from 25 to 50 atomic %, and an adjoining second layer with a boron content from 1 to 20 atomic %. One of the first and second layers in each of the free layer and reference layer contacts the tunnel barrier. Each boron containing layer has a thickness of 1 to 10 Angstroms and may include one or more B layers and one or more Co, Fe, CoFe, or CoFeB layers. As a result, migration of non-magnetic metals along crystalline boundaries to the tunnel barrier is prevented, and the MTJ has a low defect count of around 10 ppm while maintaining an acceptable TMR ratio following annealing to temperatures of about 400° C. The boron containing layers are selected from CoB, FeB, CoFeB and alloys thereof including CoFeNiB.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.