Researchers at Tohoku University demonstrated a high-speed spin-orbit-torque MRAM (SOT-MRAM) memory cell compatible with 300 mm Si CMOS technology.
The SOT device achieved high-speed switching (down to 0.35 ns) and a high thermal stability factor (E/kBT 70) which the researchers say is sufficient for high speed non-volatile memory applications. The device can withstand annealing at 400°C. The researchers used these devices to create a complete SOT-MRAM memory cell.
In SOT-MRAM, or spin-orbit torque MRAM, the switching of the free magnetic layer is done by injecting an in-plane current in an adjacent SOT layer, unlike STT-MRAM where the current is injected perpendicularly into the magnetic tunnel junction and the read and write operation is performed through the same path. SOT-MRAM promises to be faster, denser and more efficient. In 2018 researchers from Imec fabricated SOT-MRAM devices on 300mm wafers using CMOS compatible processes, for the first time.