Atomic layer deposition and atomic layer etching enable advanced spintronics fabrication
A research team led by Dr Shao-Jie Hu at the Center for Spintronics and Quantum Systems at Xi’an Jiaotong University, China, have recently published a review article highlighting the exciting potential for applying ALD and ALE to different materials to fabricate improved spintronic devices.
Dr Shao-Jie Hu completed his PhD on electrically and thermally driven spin-dependent transports in ferromagnetic/nonmagnetic hybrid nanostructures at the Electrical and Electronic Engineering department at Kyushu University, Japan, in March 2015. Currently, at Xi’an Jiaotong University, he works on the theory of electron, heat and spins transportation in ferromagnetic/nonmagnetic junctions, the characterization of spin current related effects (such as the Spin Hall effect, Spin-dependent Seebeck effect, Hanle effect, Spin transfer torque effect) and the development of fabrication process for Micro/Nano spintronic devices.
Interestingly, the Xi’an Jiaotong University has roots going back to 1896. The Faculty of Material Science and Engineering was set up in 1952 and the State Key Laboratory for Mechanical Behaviour of Materials was founded in 1963. There are 58 faculty members in this lab, including 26 professors and 25 vice professors. Their research involves four major areas: characterization and evaluation of mechanical properties; strength of surface layers and interfacial strength; high-performance materials and their application; materials performance under harsh conditions.
The review titled ‘Recent Progress of Atomic Layer Technology in Spintronics: Mechanism, Materials and Prospects’ provides a broad overview of atomic layer technology while illuminating the various principles that underpin it and the mechanisms of ALD and ALE. The authors give an overview of the most recent applications of ALD in spintronics, along with an interesting summary of the timeline of the developments. They further discuss how ALD and ALE can be used for several material systems, such as insulators, semiconductors, metals, and the recently developed two-dimensional van der Waals materials. They also offer an interesting comparison of ALD and ALE and what can be learnt from ALD to further develop ALE.
An example of the evolution of ALD techniques used for the fabrication of tunnel barriers for magnetic tunnel junctions is shown in Fig. 1.
Figure 2 shows how an Al2O3 tunnel barrier was made for a graphene-coated MTJ.
The original document can be found here