论文信息 - Suppression of Switching-Field Variation by Surface Oxidation Depending on the Shape of the CoFeB Free Layer

Suppression of Switching-Field Variation by Surface Oxidation Depending on the Shape of the CoFeB Free Layer

We investigated the suppression of the variation of switching field Hsw by reducing magnetization M in submicron-sized magnetic tunnel junctions (MTJs) by oxidizing the surface of the CoFeB layer. Examination confirmed a reduction in the M of oxidized CoFeB film. The results also confirmed that oxidization enlarges anisotropy field Hk of CoFeB films. We applied this film to the free layer of submicron-sized MTJs of various aspect ratios. The results revealed that Hsw variation depending on the aspect ratio is reduced more with oxidation than without. We confirmed that Hsw variation in submicron-sized MTJs originating in the CoFeB free layer's shape decreased due to the oxidation, which reduced the switching field distribution (SFD) for the MTJs

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