2020/08/05 by Fabio Giudice, Jonathan Becker, del Giudice, Fabio +14 · 1 citation
Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Nanowire Synthesis and Applications #Surface and Thin Film Phenomena
paper · pdf · doi:10.48550/arxiv.2008.02350
openalex publication_date 2020/08/05 · openalex created_date 2022/07/26 · openalex updated_date 2026/07/28
Ultrathin InAs nanowires (NW) with one-dimensional (1D) sub-band structure\nare promising materials for advanced quantum-electronic devices, where\ndimensions in the sub-30 nm diameter limit together with post-CMOS integration\nscenarios on Si are much desired. Here, we demonstrate two site-selective\nsynthesis methods that achieve epitaxial, high aspect ratio InAs NWs on Si with\nultrathin diameters below 20 nm. The first approach exploits direct vapor-solid\ngrowth to tune the NW diameter by interwire spacing, mask opening size and\ngrowth time. The second scheme explores a unique reverse-reaction growth by\nwhich the sidewalls of InAs NWs are thermally decomposed under controlled\narsenic flux and annealing time. Interesting kinetically limited dependencies\nbetween interwire spacing and thinning dynamics are found, yielding diameters\nas low as 12 nm for sparse NW arrays. We clearly verify the 1D sub-band\nstructure in ultrathin NWs by pronounced conductance steps in low-temperature\ntransport measurements using back-gated NW-field effect transistors. Correlated\nsimulations reveal single- and double degenerate conductance steps, which\nhighlight the rotational hexagonal symmetry and reproduce the experimental\ntraces in the diffusive 1D transport limit. Modelling under the realistic\nback-gate configuration further evidences regimes that lead to asymmetric\ncarrier distribution and lifts of the degeneracy in dependence of gate bias.\n