Nanoscale Magnetic Tunnel Junctions Fabricated Using Etching-Back Technique

Magnetic tunnel junctions (MTJs) have gained significant attention due to their versatile applications in next-generation information storage, high-sensitivity sensors, and neuromorphic computing systems. The precise and high-quality fabrication of MTJ devices in laboratory settings is crucial for driving advancements in MTJ research. This study introduces a high-precision, cost-effective, and efficient fabrication method for nanoscale MTJ devices by integrating metal hard mask etching (etch-back) with conventional lithography techniques. This approach enables the production of devices with nanopillar dimensions as small as 100 nm, achieving a remarkable 100% yield. The fabricated devices demonstrate outstanding performance metrics, including a resistance–area (RA) product of $23~\Omega \cdot \mu $ m2, a tunneling magnetoresistance (TMR) ratio of 110%, reliable spin-transfer torque (STT)-induced switching behavior, and a robust spin-torque diode effect. This work offers a practical and scalable pathway for the cost-effective laboratory fabrication of nanoscale MTJ devices, paving the way for further advancements in spintronic technologies.