Magnetic field sensor, system, and oblique incident deposition fabrication method

US11280855B2 · kind B2 · utility

Assignee

• NXP B.V. · NL

Inventors

• Stephan Marauska · Kaltenkirchen, DE
• Jörg Kock · Burgwedel, DE

Key dates

• Filing date: Jul 29, 2019
• Grant date: Mar 22, 2022
• Expiry date: Aug 4, 2040

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/091
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A magnetic field sensor includes at least two magnetoresistive (MR) sensor elements arranged in a half-bridge configuration. Each of the MR sensor elements includes a magnetic region having a magnetic anisotropy with a resultant magnetization. The magnetic anisotropy is created using an oblique incident deposition (OID) technique, with the magnetic regions being deposited at a nonzero deposition angle relative to a reference line oriented perpendicular to a surface of the magnetic field sensor. A system includes an encoder and the half-bridge configuration of the sensor elements. The encoder produces an external magnetic field, having predetermined magnetic variations in response to motion of the encoder, the magnetic field being detectable by the sensor elements. The resultant magnetization of the sensor elements is aligned by OID in a preferred direction perpendicular to the direction of the external magnetic field instead of utilizing a permanent magnet structure for providing a bias magnetic field.