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 a spin transfer torque-based magnetoresistive random access memory (STT-MRAM) cell (one transistor, one magnetic tunnel junction – 1T-1MTJ) on an 8-inch process platform. By combining a 0.5 μm CMOS front end of line process and STT-MTJ back end of line process, a 1T-1MTJ device with an MTJ of approximately 80 nm is realized. The Resistance(R)-magnetic field(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 an STT-MRAM with dual CoFeB/MgO interface free layer. Our findings demonstrate the potential for application in ultra-low-power portable mobile devices and embedded systems.