How do MTJs work?
MTJs operate based on the principle of
quantum tunneling. When a voltage is applied across the junction, electrons can tunnel through the insulating barrier, with the tunneling probability depending on the relative orientation of the magnetizations in the ferromagnetic layers. If the magnetizations are parallel, the tunneling resistance is low, resulting in a high current. Conversely, if the magnetizations are antiparallel, the resistance is high, leading to a low current. This phenomenon is known as
Tunnel Magnetoresistance (TMR).
What are the benefits of using MTJs?
MTJs offer several advantages, including high speed, low power consumption, and non-volatility. They can withstand high radiation levels, making them suitable for
space applications and other harsh environments. Moreover, the scalability of MTJs to nanometer dimensions aligns well with the ongoing trends in miniaturization and
Moore's Law.
What challenges do MTJs face?
Despite their advantages, MTJs face challenges such as thermal stability and variability in
manufacturing processes. The precise control of the thickness and quality of the insulating barrier is critical. Additionally, achieving high TMR values and ensuring consistent performance across large arrays of MTJs remain key areas of research.
How are MTJs fabricated?
The fabrication of MTJs involves techniques like
sputtering and
atomic layer deposition (ALD) to deposit the ferromagnetic and insulating layers with nanometer precision. Advanced lithography methods are employed to pattern the junctions, followed by etching and other processes to define the final device structure.
