First Demonstration of Field Free Switching Perpendicular SOT-MRAM 4kb Array Using Z-Spin

Abstract

In a fully integrated 300 mm platform for perpendicular Spin-Orbit Torque Magnetoresistive RAM (SOT-MRAM), we demonstrate field-free functionality in a 4kb characterization array. Our results show that a stack design of a ferromagnet (FM) / Ta bilayer track enables Z-Spin based switching on SOT-MRAM devices in the <10ns regime. Furthermore, our devices show tunneling magnetoresistance (TMR) > 90% and retention >10 years, which is comparable to a standard field assisted SOT device. The devices integrated in 4kb sub-bank array configurations show excellent distributions and low variability between dies, paving the way for advanced memory applications of SOT-MRAM.