Tunnel Мagnetoresistive Еlements for Magnetic Field Sensors

Abstract

We have developed technology for manufacturing chains of CoFe/Al₂O₃/NiFe tunnel magnetoresistive (TMR) elements with pinning on the IrMn antiferromagnetic layer. We have studied the dependence of the shape of magnetoresistance curves on the geometric parameters of laterally bounded TMR contacts, as well as on the mutual orientation of the external magnetic field and the axis of unidirectional anisotropy of the pinned CoFe layer. The chain resistance ranges from several tens of kiloohms to hundreds of megaohms depending on the thickness of the tunnel-transparent dielectric layer with a magnetoresistive effect of 10–15%. The developed technology can be used in manufacturing tunneling magnetic field sensors.