The fabrication of spin transfer torque-based magnetoresistive random access memory cell with ultra-low switching power

Abstract

We conducted research on the integration technology of STT-MRAM (Spin Transfer Torque-Based Magnetoresistive Random Access Memory) memory cell (1 Transistor - 1 Magnetic Tunnel Junction, 1T-1MTJ) on an 8-inch process platform. By combining 0.5μm CMOS FEOL(Front End Of Line) process and STT-MTJ BEOL(Back End Of Line) process, 1T-1MTJ device with the MTJ sized about 80 nm is realized. The R-H measurement reveals a coercive force of approximately 450 Oe for the MTJ. Nevertheless, the 1T-1MTJ device exhibits a critical switching current of 4.7 μA (from high to low resistance state) and 17.9 μA (from low to high resistance state), accompanied by corresponding critical switching voltages of 0.05 V and 0.16 V, respectively, which is extremely low in STT-MRAM with dual CoFeB/MgO interface free layer. Our findings hold the potential for application in ultra-low-power portable mobile devices and embedded systems.