講演情報
[14p-K302-4]Micromagnetic simulation study on the stability of sub-nano second magnetization switching for the long-axis angle of 75° in SOT-MRAM
〇(D)Joonsoo Kim1, Hiroshi Naganuma2, Thi Van Anh Nguyen1, Tetsuo Endoh1 (1.Tohoku Univ., 2.Nagoya Univ.)
キーワード：
Spintronics、SOT-MRAM、Spin device
Spin-Orbit Torque Magnetic Random Access Memory (SOT-MRAM) is a promising candidate for next-generation non-volatile memory due to its fast-switching speed, low power consumption, and scalability. This presentation focuses on the effects of the long-axis tilt angle of magnetic tunnel junction (MTJ) with ellipse shape on the magnetization switching behavior in the SOT-MRAM devices, analyzed through micromagnetic simulations. The micromagnetic simulations1) were conducted to evaluate the stability and efficiency of sub-nanosecond magnetization switching under varying voltage levels and long-axis tilt angles. [Fig. 1] The results reveal that at smaller tilt angles, such as 15°, the generation of spin torque decreases during the initiation of magnetization switching but increases significantly near the end of the process. This uneven behavior leads to back-hopping and destabilizes the magnetization switching. In contrast, a tilt angle of 75° achieves optimal performance, enabling fast and stable magnetization switching. The stability switching is due to reducing spin torque just after switching. The quantitative analysis of spin torque coefficients highlights the critical role of angle-dependent spin torque generation in achieving reliable switching at 75°. This work provides a detailed understanding of angle-dependent magnetization switching in SOT-MRAM devices and underscores the importance of structural design for enhancing device performance.