Dipolar core-shell cells with enhanced write speed and reduced cross-talk of perpendicular shape anisotropy MRAM
Résumé
The concept of Perpendicular Shape-Anisotropy Spin-Transfer-Torque Magnetic Random-Access Memory (PSA-STT-MRAM)
tackles the downsize scalability limit of conventional ultrathin magnetic tunnel junctions (MTJ) below sub-20 nm technological
nodes. It is based on a thick storage layer, enhancing the thermal stability factor ∆ of the device via perpendicular shape anisotropy.
However, this comes at the expense of a tendency for a non-reversal mechanism, increasing the switching time and capping the
stability of the device versus aspect ratio. Besides, the high aspect ratio and volume supporting thermal stability significantly increase
the stray field in neighbouring bits in comparison with the conventional MTJs, in the case of dense arrays. In this work, we show
that, by making use of a dipolar-coupled core-shell structure as a storage layer for the PSA-MTJ, both the reversal mechanism
and stray field challanges are largely improved. We use macrospin simulations in an array to show the decrease in stray field, and
micromagnetic simulations to show the faster switching times while avoiding the domain-wall limit, for a given thermal stability.
Domaines
Physique [physics]Origine | Fichiers produits par l'(les) auteur(s) |
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