Reliable Sub-Nanosecond Switching in Magnetic Tunnel Junctions for MRAM Applications

We demonstrate reliable sub-nanosecond switching in two-terminal spin transfer torque magnetoresistive random access memory (STT-MRAM) devices by using double spin-magnetic tunnel junctions (DS-MTJs). A write-error-rate (WER) of <tex-math notation="LaTeX">1E -6 </tex-math> was achieved in 194 devices with 250-ps write pulses and tight distributions. The WER = <tex-math notation="LaTeX">1E -6 </tex-math> was also demonstrated over a temperature range of −40 °C–85 °C in a single device with 225-ps write pulses. No degradation was observed after <tex-math notation="LaTeX">1E10 </tex-math> write cycles in selected single devices, written with 250-ps write pulses. We compare the DS-MTJ device switching performance with the published results from the state-of-the-art three-terminal spin–orbit torque (SOT) MRAM devices and show a <tex-math notation="LaTeX">10× </tex-math> reduction in switching current density ( <tex-math notation="LaTeX">Jc </tex-math> ) and 3– <tex-math notation="LaTeX">10× </tex-math> reduction in power consumption for devices with similar energy barriers ( <tex-math notation="LaTeX">Eb </tex-math> ).