Description of statistical switching in perpendicular STT-MRAM within an analytical and numerical micromagnetic framework

TL;DR

This paper develops an analytical and numerical framework to accurately model stochastic switching in perpendicular STT-MRAM, emphasizing the importance of data-driven design and full micromagnetic simulations for reliable device performance predictions.

Contribution

It introduces an analytical formulation accounting for spin-torque asymmetry and validates it against micromagnetic simulations, highlighting the use of Pearson Type IV PDF for switching time distribution.

Findings

Analytical model matches micromagnetic simulation results.

Pearson Type IV PDF effectively fits switching time data.

Full micromagnetic simulations are essential for accurate statistical modeling.

Abstract

The realistic modeling of STT-MRAM for the simulations of hybrid CMOS/Spintronics devices in comprehensive simulation environments require a full description of stochastic switching processes in state of the art STT-MRAM. Here, we derive an analytical formulation that takes into account the spin-torque asymmetry of the spin polarization function of magnetic tunnel junctions studying. We studied its validity range by comparing the analytical formulas with results achieved numerically within a full micromagnetic framework. We also find that a reasonable fit of the probability density function (PDF) of the switching time is given by a Pearson Type IV PDF. The main results of this work underlines the need of data-driven design of STT-MRAM that uses a full micromagnetic simulation framework for the statistical proprieties PDF of switching processes.