Enhancing Magnetic Immunity of STT-MRAM with Magnetic Shielding

We present the first magnetic shielding study including design, modeling, fabrication and characterization of package level magnetic shield for perpendicular spin-transfer torque magneto resistive random-access memory (STT-MRAM). Magnetic shielding improves the magnetic immunity of STT-MRAM against the applied external perpendicular magnetic field by three times. It improves the bit error rate by more than four orders at an applied external perpendicular magnetic field of 500 Oe and without ECC turned on. Modeled a keep out zone of 1mm for MTJ, corresponding to wire-bond window opening of 0.7mm.