Spin-transfer-torque efficiency enhanced by edge-damage of perpendicular magnetic random access memories

TL;DR

This study demonstrates that edge damage in perpendicular MRAM cells can significantly improve spin-transfer-torque efficiency by reducing switching current while maintaining thermal stability, highlighting the importance of edge control for optimization.

Contribution

The paper reveals that magnetic and electrical edge damages can enhance STT efficiency by altering switching modes and reducing switching current in perpendicular MRAM.

Findings

Edge damage changes switching mode, reducing switching current.

Edge damage slightly decreases thermal stability.

Enhanced STT efficiency observed with edge damage.

Abstract

We numerically investigate the effect of magnetic and electrical damages at the edge of a perpendicular magnetic random access memory (MRAM) cell on the spin-transfer-torque (STT) efficiency that is defined by the ratio of thermal stability factor to switching current. We find that the switching mode of an edge-damaged cell is different from that of an undamaged cell, which results in a sizable reduction in the switching current. Together with a marginal reduction of the thermal stability factor of an edge-damaged cell, this feature makes the STT efficiency large. Our results suggest that a precise edge control is viable for the optimization of STT-MRAM.