Time-Resolved Switching Characteristic in Magnetic Tunnel Junction with Spin Transfer Torque Write Scheme

The time-resolved switching characteristics of 100×200 nm 2 size CoFeB/MgO/CoFeB-based magnetic tunnel junction (MTJ) are investigated by using the 20 GHz sampling measurement technique. We focused on the physical quantities of the time-resolved characteristics such as incubation time t A , transit time t B , and the standard deviations σ V 's of the period of the switching waveform. Furthermore, the dependencies of t A and t B on the applied pulse waveforms are analyzed. We found t A exponentially decreases as the applied voltage to MTJ increases, while t B remains less than two nano seconds regardless of the applied voltage. Furthermore, it is observed that the standard deviations of the waveform during t A is larger than that of the other periods. Finally, we discuss the switching characteristics with proposed toy model based on spin transfer torque (STT) phenomena.