Monolayer longitudinal bias and sensor trackwidth definition for overlaid anisotropic and giant magnetoresistive heads
US5949623A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 11, 1997 |
| Grant date | Sep 7, 1999 |
| Priority date | — |
| Expiry date | Sep 11, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49021
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetoresistive (MR) head and a method are disclosed providing a longitudinal bias layer and conductor leads at end regions of sensor elements to form a sensor region between the end regions. A uniform longitudinal bias thin film layer is deposited overlaying the entirety of the upper MR sensor, and a uniform conductor thin film layer is deposited overlaying the entirety of the longitudinal bias thin film layer. A photoresist process is conducted over the conductor thin film layer to develop a mask of the end regions and to expose a central region between the end regions. A reactive-ion-etching process completely etches the conductor thin film layer in the exposed central region to expose the longitudinal bias layer in the central region, the photoresist mask is removed, and an ion milling process of the exposed longitudinal bias layer at the central region reduces the bias layer from a "bias" critical thickness to a "null" critical thickness to free the MR sensor elements, thereby forming a defined sensor region of the underlying MR sensor elements at the exposed longitudinal bias layer at the central region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.