AVS 61st International Symposium & Exhibition
    Thin Film Tuesday Sessions
       Session TF+AS+EM-TuA

Paper TF+AS+EM-TuA1
A Statistical Optimization of Perpendicular Anisotropy and Damping for Ta-Inserted Double CoFeB/MgO Interface MTJ’s

Tuesday, November 11, 2014, 2:20 pm, Room 305

Session: Thin Film: Growth and Characterization II
Presenter: Samuel Schwarm, University of Alabama
Authors: S. Gupta, University of Alabama
S. Schwarm, University of Alabama
B. Clark, University of Alabama
Correspondent: Click to Email
A statistical Design of Experiments was conducted on double-interface Ta-inserted CoFeB-MgO magnetic tunnel junctions (MTJ’s). These MTJ’s were deposited using a Shamrock planetary sputtering system. The thicknesses of the inserted Ta and the CoFeB electrodes were varied using Response Surface Methodology. The responses measured using magnetometry and ferromagnetic resonance were a) effective magnetization, b) damping constant and c) perpendicular anisotropy. The effect of annealing on the perpendicular anisotropy was also observed for these devices. As the Ta thickness is increased for fixed CoFeB thickness, the M-H loops indicate that the anisotropy is becoming perpendicular. After annealing, both magnetometry and FMR results show that the MTJ’s indicate full perpendicular anisotropy. Interfacial perpendicular anisotropy, which can be extracted from the FMR measurements, scales with the inserted Ta thickness for both as-deposited and annealed samples.