Two-axis magnetic field sensor having reduced compensation angle for zero offset

US8647891B2 · kind B2 · utility

Assignee

• Everspin Technologies, Inc. · US

Inventors

• Jijun Sun · Saku, JP
• Phillip Mather · Phoenix, US
• Srinivas V. Pietambaram · Gilbert, US
• Jon Slaughter · Tempe, US
• Renu Whig · Chandler, US
• Nicholas Rizzo · Gilbert, US

Key dates

• Filing date: Jun 4, 2013
• Grant date: Feb 11, 2014
• Expiry date: Jun 4, 2033

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T29/49117
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A sensor and fabrication process are provided for forming reference layers with substantially orthogonal magnetization directions having zero offset with a small compensation angle. An exemplary embodiment includes a sensor layer stack of a magnetoresistive thin-film based magnetic field sensor, the sensor layer stack comprising a pinning layer; a pinned layer including a layer of amorphous material over the pinning layer, and a first layer of crystalline material over the layer of amorphous material; a nonmagnetic coupling layer over the pinned layer; a fixed layer over the nonmagnetic coupling layer; a tunnel barrier over the fixed layer; and a sense layer over the nonmagnetic intermediate layer. Another embodiment includes a sensor layer stack where a pinned layer including two crystalline layers separated by a amorphous layer.