Shadow Epitaxy for In Situ Growth of Generic Semiconductor/Superconductor Hybrids

Damon J. Carrad, Martin Bjergfelt, Thomas Kanne, Martin Aagesen, Filip Krizek, Elisabetta M. Fiordaliso, Erik Johnson, Jesper Nygard*, Thomas Sand Jespersen*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Uniform, defect-free crystal interfaces and surfaces are crucial ingredients for realizing high-performance nanoscale devices. A pertinent example is that advances in gate-tunable and topological superconductivity using semiconductor/superconductor electronic devices are currently built on the hard proximity-induced superconducting gap obtained from epitaxial indium arsenide/aluminum heterostructures. Fabrication of devices requires selective etch processes; these exist only for InAs/Al hybrids, precluding the use of other, potentially superior material combinations. This work introduces a crystal growth platform-based on 3D structuring of growth substrates-which enables synthesis of semiconductor nanowire hybrids with in situ patterned superconductor shells. The platform eliminates the need for etching, thereby enabling full freedom in the choice of hybrid constituents. All of the most frequently used superconducting hybrid device architectures are realized and characterized. These devices exhibit increased yield and electrostatic stability compared to etched devices, and evidence of ballistic superconductivity is observed. In addition to aluminum, hybrid structures based on tantalum, niobium, and vanadium are presented.
Original languageEnglish
Article numbere1908411
JournalAdvanced Materials
Number of pages9
ISSN0935-9648
DOIs
Publication statusPublished - 2020

Cite this

Carrad, D. J., Bjergfelt, M., Kanne, T., Aagesen, M., Krizek, F., Fiordaliso, E. M., Johnson, E., Nygard, J., & Jespersen, T. S. (2020). Shadow Epitaxy for In Situ Growth of Generic Semiconductor/Superconductor Hybrids. Advanced Materials, [e1908411]. https://doi.org/10.1002/adma.201908411