Method for making a magnetoresistive sensor having a cobalt-ferrite pinning layer
US6928723B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 2003 |
| Grant date | Aug 16, 2005 |
| Priority date | — |
| Expiry date | Feb 16, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49071
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An exchange-coupled magnetic structure of a cobalt-ferrite layer adjacent a magnetic metal layer is used in magnetorestive sensors, such as spin valves or tunnel junction valves. The exchange-coupled magnetic structure is used in a pinning structure pinning the magnetization of a ferromagnetic pinned layer, or in an AP pinned layer. A low coercivity ferrite may be used in an AP free layer. Cobalt-ferrite layers may be formed by co-sputtering of Co and Fe in an oxygen/argon gas mixture, or by sputtering of a CoFe2 composition target in an oxygen/argon gas mixture. Alternatively, the cobalt-ferrite layer may be formed by evaporation of Co and Fe from an alloy source or separate sources along with a flux of oxygen atoms from a RF oxygen atom beam source. Magnetoresistive sensors including cobalt-ferrite layers have small read gaps and produce large signals with high efficiency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.