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

Abstract

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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1{E} -6$ </tex-math></inline-formula> was achieved in 194 devices with 250-ps write pulses and tight distributions. The WER = <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1{E} -6$ </tex-math></inline-formula> 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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1{E}10$ </tex-math></inline-formula> 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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10\times $ </tex-math></inline-formula> reduction in switching current density ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${J}_{\text {c}}$ </tex-math></inline-formula> ) and 3– <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10\times $ </tex-math></inline-formula> reduction in power consumption for devices with similar energy barriers ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{\text {b}}$ </tex-math></inline-formula> ).