Unipolar switching of perpendicular mtj for STT-MRAM application

Traditional spin transfer torque MRAM (STT-MRAM) uses one transistor and one MTJ (1T-1MTJ) architecture, where the transistor provides bi-polar currents to switch the magnetization of the free layer of the MTJ. Due to the limitation of the maximum current that is available from a typical transistor, for a MTJ device with required thermal stability and data retention at extreme densities, the size of the transistor that is needed to provide a high enough current to switch the magnetization of the free layer of the MTJ may impose an ultimate limitation on the STT-MRAM area data density that can be achieved.