Low resistance tunneling magnetoresistive sensor with composite inner pinned layer
US8008740B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 2009 |
| Grant date | Aug 30, 2011 |
| Priority date | — |
| Expiry date | Sep 23, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F10/3295
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A high performance TMR sensor is fabricated by employing a composite inner pinned (AP1) layer in an AP2/Ru/AP1 pinned layer configuration. In one embodiment, there is a 10 to 80 Angstrom thick lower CoFeB or CoFeB alloy layer on the Ru coupling layer, a and 5 to 50 Angstrom thick Fe or Fe alloy layer on the CoFeB or CoFeB alloy, and a 5 to 30 Angstrom thick Co or Co rich alloy layer formed on the Fe or Fe alloy. A MR ratio of about 48% with a RA of <2 ohm-um2 is achieved when a CoFe AP2 layer, MgO (NOX) tunnel barrier, and CoFe/NiFe free layer are used in the TMR stack. Improved RA uniformity and less head noise are observed. Optionally, a CoFe layer may be inserted between the coupling layer and CoFeB or CoFeB alloy layer to improve pinning strength and enhance crystallization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.