US 12,174,276 B2
Magnetoresistive element for a 2D magnetic sensor having a reduced hysteresis response
Andrey Timopheev, Vif (FR); Nikita Strelkov, Meylan (FR); and Jeffrey Childress, San Jose, CA (US)
Assigned to Allegro MicroSystems, LLC, Manchester, NH (US)
Appl. No. 18/245,380
Filed by Allegro MicroSystems, LLC, Manchester, NH (US)
PCT Filed Sep. 14, 2021, PCT No. PCT/IB2021/058336
§ 371(c)(1), (2) Date Mar. 15, 2023,
PCT Pub. No. WO2022/058875, PCT Pub. Date Mar. 24, 2022.
Claims priority of application No. 20315414 (EP), filed on Sep. 18, 2020.
Prior Publication US 2023/0296703 A1, Sep. 21, 2023
Int. Cl. G01R 33/09 (2006.01)
CPC G01R 33/098 (2013.01) 14 Claims
OG exemplary drawing
 
1. A magnetoresistive element for a 2D magnetic sensor, the magnetoresistive element comprising a tunnel barrier layer included between a reference layer having a reference magnetization and a sense layer having a sense magnetization;
wherein the sense layer comprises a synthetic antiferromagnetic (SAF) structure including a ferromagnetic first sense sublayer in contact with the tunnel barrier layer and separated from a ferromagnetic second sense sublayer by a first non-magnetic spacer layer such that the first sense sublayer is antiferromagnetically coupled to the second sense sublayer;
wherein the sense layer is configured such that a sense magnetic ratio ΔM is defined as:

OG Complex Work Unit Math
wherein MSFM1 and MSFM2 are the spontaneous magnetizations of, respectively, the first and second sense sublayers and tFM1 and tFM2 are the thicknesses of, respectively, the first and second sense sublayers;
wherein the sense magnetic ratio ΔM is between 0.1 and 0.25; and
wherein the second sense sublayer comprises a spontaneous magnetization that increases with increasing distance from the sense spacer layer.