Tunneling magneto-resistive read head with two-piece free layer
US6795280B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 1999 |
| Grant date | Sep 21, 2004 |
| Priority date | — |
| Expiry date | Nov 17, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/3996
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for a recording head using a spin-dependent tunneling (SDT) junction. The SDT junction utilizes an aluminum oxide tunnel barrier. The tunnel barrier can be formed to a thickness comparable with a typical Cu spacer layer on a spin valve. With the SDT junction, current is applied perpendicular to the plane of the film. The SDT junctions can have high magneto-resistance up to 40%. The magnetoresistive qualities of a head design incorporating the SDT junction are not directly related to head resistance, head geometry, bias current and film thickness. The method can include forming a spin tunnel barrier by fashioning a stack into a bottom electrode, defining a junction, depositing a layer of insulator, performing a photoprocess, depositing an upper electrode layer and lifting off the top electrode layer to define the electrode. The stack can include a pinned layer, a barrier layer and a free layer. The pinned layer can include NiFe. The barrier layer can include AlOx. The free layer can include Co. The junction can be defined with an ion mill and the insulator can include Al2O3. In addition, the top electrode layer can include Cu.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.