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MA: Fachverband Magnetismus

MA 23: Poster Magnetism I

MA 23.59: Poster

Tuesday, March 28, 2023, 17:00–19:00, P1

Dependence of resistance area product and tunnel magnetoresistance on MgO crystalline quality in CoFeB/ MgO/ CoFeB Magnetic Tunnel Junctions — •Tobias Peters und Günter Reiss — Center for Spinelectronic Materials and Devices, University of Bielefeld, Germany

We investigated the tunnel magnetoresistance (TMR) and resistance area product (RA) in CoFeB/MgO/CoFeB magnetic tunnel junctions (MTJs) grown via sputtering deposition and investigated the influence of MgO crystalline quality. Therefore, the Ar-pressure was varied from 0.004 mbar to 0.14 mbar during the MgO deposition. X-ray diffraction (XRD) measurements performed on pseudo spin valves with 10nm thick MgO reveal the highest (001) oriented crystallographic texture of MgO for an Ar-pressure of 0.08 mbar. This MgO sputtering conditions transfered to exchange biased MTJs provides the best barrier quality, which resulted in the lowest RA (17 Ω µ m²) with high TMR ratio (198%) for a MgO thickness of 0.8nm. Additionally we found higher Ar partial pressure (above 0.14 mbar) resulting in amorphous MgO with even lower RA (5 Ω µ m²), but with significantly reduced TMR ratio (74%).