CoFeB/MgO-based magnetic tunnel junction directly formed on a flexible substrate

Shinya Ota, Masaki Ono, Hiroki Matsumoto, Akira Ando, Tsuyoshi Sekitani, Ryuhei Kohno, Shogo Iguchi, Tomohiro Koyama and Daichi Chiba

We succeeded in fabricating a CoFeB/MgO-based magnetic tunnel junction (MTJ) directly on an organic flexible substrate. The MTJ shows good strain endurance while keeping the tunnel magnetoresistance (TMR) ratio of ~100% under various strained conditions; the TMR ratio is almost unchanged up to a tensile strain of 1.2%. Because of the magnetoelastic effect, the magnetic anisotropy fields for the top and bottom CoFeB layers are linearly proportional to strain with almost the same rate as that in a single CoFeB film, suggesting that the expected strain is added on both CoFeB layers in the MTJ pillar from the stretched flexible substrate.

Applied Physics Express:

It was elected by Spotlights of the APEX