Title
Growth of α-Sn on silicon by a reversed β-Sn to α-Sn phase transformation for quantum material integration
Author
Shang Liu, Alejandra Cuervo Covian, Jules A. Gardener, Austin Akey, Barnaby D. A. Levin, Xiaoxin Wang & Jifeng Liu
Year
2022
Journal
Communications Materials
Abstract
α-Sn and SnGe alloys are attracting attention as a new family of topological quantum materials. However, bulk α-Sn is thermodynamically stable only below 13∘C. Moreover, scalable integration of α-Sn quantum materials and devices on silicon is hindered by their large lattice mismatch. Here, we grow compressively strained α-Sn doped with 2-4 at.% germanium on a native oxide layer on a silicon substrate at 300–500∘C. Growth is found to occur by a reversed β-Sn to α-Sn phase transformation without relying on epitaxy, with germanium-rich GeSn nanoclusters in the as-deposited material acting as seeds. The size of α-Sn microdots reaches up to 200 nm, which is approximately ten times larger than the upper size limit for α-Sn formation reported previously. Furthermore, the compressive strain makes it a candidate 3D topological Dirac semimetal with possible applications in spintronics. This process can be further optimized to achieve optically tunable SnGe quantum material and device integration on silicon.
Full Article
Instrument
V-570
Keywords
quantum materials, device, silicon, GeSn nanoclusters