Two-axis magnetic field sensor with substantially orthogonal pinning directions
US8257596B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 2009 |
| Grant date | Sep 4, 2012 |
| Priority date | — |
| Expiry date | Jun 16, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/4902
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fabrication process and apparatus provide a high-performance magnetic field sensor (200) from two differential sensor configurations (201, 211) which require only two distinct pinning axes (206, 216) which are formed from a single reference layer (60) that is etched into high aspect ratio shapes (62, 63) with their long axes drawn with different orientations so that, upon treating the reference layer with a properly aligned orienting field (90) and then removing the orienting field, the high aspect ratio patterns provide a shape anisotropy that forces the magnetization of each patterned shape (62, 63) to relax along its respective desired axis. Upon heating and cooling, the ferromagnetic film is pinned in the different desired directions by one of 1) tailoring the intrinsic anisotropy of the reference layer during the depositing step, 2) forming a long axes of one of the patterned shapes (62, 63) at a non-orthogonal angle to the long axes of the other patterned shape (62, 63) when etched, or 3) applying a compensating field when pinning the reference layers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.