Micromachines (Aug 2023)

A Comprehensive Study of Temperature and Its Effects in SOT-MRAM Devices

  • Tomáš Hadámek,
  • Nils Petter Jørstad,
  • Roberto Lacerda de Orio,
  • Wolfgang Goes,
  • Siegfried Selberherr,
  • Viktor Sverdlov

DOI
https://doi.org/10.3390/mi14081581
Journal volume & issue
Vol. 14, no. 8
p. 1581

Abstract

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We employ a fully three-dimensional model coupling magnetization, charge, spin, and temperature dynamics to study temperature effects in spin-orbit torque (SOT) magnetoresistive random access memory (MRAM). SOTs are included by considering spin currents generated through the spin Hall effect. We scale the magnetization parameters with the temperature. Numerical experiments show several time scales for temperature dynamics. The relatively slow temperature increase, after a rapid initial temperature rise, introduces an incubation time to the switching. Such a behavior cannot be reproduced with a constant temperature model. Furthermore, the critical SOT switching voltage is significantly reduced by the increased temperature. We demonstrate this phenomenon for switching of field-free SOT-MRAM. In addition, with an external-field-assisted switching, the critical SOT voltage shows a parabolic decrease with respect to the voltage applied across the magnetic tunnel junction (MTJ) of the SOT-MRAM cell, in agreement with recent experimental data.

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