Method for making a magnetoresistive read transducer
US4940511A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 1989 |
| Grant date | Jul 10, 1990 |
| Priority date | — |
| Expiry date | May 22, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49046
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetoresistive (MR) read transducer comprising a thin film MR layer formed of ferromagnetic material and a nonmagnetic thin film spacer layer in contact with the MR layer. The spacer layer comprises a material selected from the group consisting of nichrome and nichrome with chromium oxide. A thin film of soft magnetic material is deposited in contact with the spacer layer so that a transverse bias is produced in at least a part of the MR layer. A feature of the invention is that the resistivity of the spacer layer can be chosen by selecting the ratio of nichrome to chromium oxide in the spacer layer. In a specific embodiment the spacer layer extends over only the central region of the MR layer. In case the MR layer is a nickel based alloy, a wet chemical etching process using an etchant comprising an aqueous solution of ceric ammonium nitrate and acetic acid can be used to pattern the spacer layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.