Reliable Sub-Nanosecond Switching in Magnetic Tunnel Junctions for MRAM Applications
Christopher Safranski, G. Hu, J. Z. Sun, Pouya Hashemi, S. Brown, L. Buzi, C. D’Emic, Eric R. J. Edwards, E. Galligan, M. Gottwald, Oki Gunawan, S. Karimeddiny, Hyunsung Jung, Juhyun Kim, K. Latzko, P. L. Trouilloud, D. C. Worledge
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> ).