CPP structure with enhanced GMR ratio
US8289661B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 4, 2011 |
| Grant date | Oct 16, 2012 |
| Priority date | — |
| Expiry date | Apr 4, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/115
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A CPP-GMR spin valve having a CoFe/NiFe composite free layer is disclosed in which Fe content of the CoFe layer ranges from 20 to 70 atomic % and Ni content in the NiFe layer varies from 85 to 100 atomic % to maintain low Hc and λS values. A higher than normal Fe content in the CoFe layer improves the MR ratio by ≧16% compared with conventional CoFe/NiFe free layers in which the Fe content in CoFe is typically <20 atomic % and the Ni content in NiFe is <85 atomic %. The CPP-GMR performance may also be optimized by incorporating a confining current path layer in the copper spacer between the pinned layer and free layer. For a pinned layer with an AP2/Ru/AP1 configuration, the spin valve performance is further improved by an AP1 layer comprised of a lamination of CoFe and Cu layers as in [CoFe/Cu]2/CoFe.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.