Structure and method for enhancing interfacial perpendicular anisotropy in CoFe(B)/MgO/CoFe(B) magnetic tunnel junctions
US8470462B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 2010 |
| Grant date | Jun 25, 2013 |
| Priority date | — |
| Expiry date | Jun 15, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1114
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A STT-RAM MTJ is disclosed with a MgO tunnel barrier formed by natural oxidation process. A Co10Fe70B20/NCC/Co10Fe70B20, Co10Fe70B20/NCC/Co10Fe70B20/NCC, or Co10Fe70B20/NCC/Co10Fe70B20/NCC/Co10Fe70B20 free layer configuration where NCC is a nanocurrent channel layer made of Fe(20%)-SiO2 is used to minimize Jc0 while enabling higher thermal stability, write voltage, read voltage, Ho, and Hc values that satisfy 64 Mb design requirements. The NCC layer is about 10 Angstroms thick to match the minimum Fe(Si) grain diameter size. The MTJ is annealed with a temperature of about 330° C. to maintain a high magnetoresistive ratio while maximizing Hk⊥(interfacial) for the free layer thereby reducing Heff and lowering the switching current. The Co10Fe70B20 layers are sputter deposited with a low pressure process with a power of about 15 Watts and an Ar flow rate of 40 standard cubic centimeters per minute to lower Heff for the free layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.