Fabrication of Graphene-Inserted Tunneling Device (GiTD) for Emerging Spin Devices

Spintronic nanostructures such as magnetic tunnel junctions possess great potential for advancing a future computing paradigm requiring high speed and low power consumption. One great challenge limiting their widespread application is the conductivity mismatch between the ferromagnet and the channel material, resulting in low spin injection efficiency. The possible use of graphene as an atomically-thin tunnel barrier has been widely discussed because it could be readily interfaced with the ferromagnet to mitigate the conductivity mismatch problem. However, it still remains relatively unexplored to quantitatively understand how graphene will impact the spin polarization of tunneling currents. Here we present the experimental process to design and fabricate a graphene-inserted tunneling device, which will serve as the useful platform to study the fundamentals required for developing emerging spin devices. Further follow-up studies such as superconducting tunneling spectroscopy can be applied to the device structure developed in this work.