Shape Defect Effect in Perpendicular Shape Anisotropy Nanodots

Abstract

Perpendicular shape anisotropy spin-transfer-torque magnetic random-access memory (PSA-STT-MRAM) demonstrates high thermal stability when size is reduced to 20 nm, which gives a new way to improve the integrity of electronic devices. This long and narrow device also poses challenges in the device fabrication process, such as sample tilt and etching defects. We used a micromagnetic simulation method to investigate the relationship between those defects and device performance. The coercivity and critical switching current density of PSA-MRAM have been calculated and analyzed with micromagnetic simulation, a three-dimensional Stoner–Wohlfarth model, and spin-filter theory. Our results demonstrate how shape defects affect the performance of the PSA-MRAM and provide guidelines for practical realization of nanoscale PSA-MRAM.