A perpendicular-anisotropy CoFeB-MgO magnetic tunnel junction

Area of Science:

• Spintronics and Nanomaterials Science
• Solid State Physics and Materials Engineering

Background:

• Magnetic tunnel junctions (MTJs) are crucial for high-density non-volatile memory and logic devices.
• Achieving perpendicular magnetic anisotropy is key for enhanced thermal stability and low switching currents.
• Existing electrode materials for perpendicular anisotropy in MTJs have limitations in simultaneously meeting thermal stability, switching current, and magnetoresistance requirements.

Discussion:

• This study leverages interfacial perpendicular anisotropy at the ferromagnetic electrode-tunnel barrier interface.
• The CoFeB-MgO material combination, known for high tunnel magnetoresistance in in-plane MTJs, is utilized.
• The approach avoids novel materials, integrating into existing MTJ fabrication processes.

Key Insights:

• Perpendicular MTJs fabricated with Ta/CoFeB/MgO/CoFeB/Ta structures exhibit a tunnel magnetoresistance ratio exceeding 120%.
• These MTJs demonstrate high thermal stability at dimensions as small as 40 nm.
• A low critical current for magnetization switching of 49 microA was achieved.

Outlook:

• The findings pave the way for realizing high-performance, energy-efficient spintronic memory and logic devices.
• Further research can optimize the CoFeB-MgO interface for even greater device performance.
• This work offers a viable path towards scalable, next-generation magnetic memory technologies.