Growth of α-Sn on silicon by a reversed β-Sn to α-Sn phase transformation for quantum material integration
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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 05, 2022
- Source ID
- 10.1038/s43246-022-00241-7
Entities
People
- Alejandra Cuervo Covian
- Austin J. Akey
- Barnaby D. A. Levin
- Jifeng Liu
- Jules A. Gardener
- Shang Liu
- Xiaoxin Wang
Organizations
- Air Force Office of Scientific Research
- National Science Foundation