TY - JOUR
T1 - Ballistic InSb Nanowires and Networks via Metal-Sown Selective Area Growth
AU - Aseev, Pavel
AU - Wang, Guanzhong
AU - Binci, Luca
AU - Singh, Amrita
AU - Stek, Lieuwe J.
AU - Bordin, Alberto
AU - Watson, John D.
AU - Boekhout, Frenk
AU - Abel, Daniel
AU - Van Hoogdalem, Kevin
AU - Kouwenhoven, Leo P.
AU - De Lange, Gijs
AU - Caroff, Philippe
PY - 2019
Y1 - 2019
N2 - Selective area growth is a promising technique to realize semiconductor-superconductor hybrid nanowire networks, potentially hosting topologically protected Majorana-based qubits. In some cases, however, such as the molecular beam epitaxy of InSb on InP or GaAs substrates, nucleation and selective growth conditions do not necessarily overlap. To overcome this challenge, we propose a metal-sown selective area growth (MS SAG) technique, which allows decoupling selective deposition and nucleation growth conditions by temporarily isolating these stages. It consists of three steps: (i) selective deposition of In droplets only inside the mask openings at relatively high temperatures favoring selectivity, (ii) nucleation of InSb under Sb flux from In droplets, which act as a reservoir of group III adatoms, done at relatively low temperatures, favoring nucleation of InSb, and (iii) homoepitaxy of InSb on top of the formed nucleation layer under a simultaneous supply of In and Sb fluxes at conditions favoring selectivity and high crystal quality. We demonstrate that complex InSb nanowire networks of high crystal and electrical quality can be achieved this way. We extract mobility values of 10000-25000 cm2 V-1 s-1 consistently from field-effect and Hall mobility measurements across single nanowire segments as well as wires with junctions. Moreover, we demonstrate ballistic transport in a 440 nm long channel in a single nanowire under a magnetic field below 1 T. We also extract a phase-coherent length of ∼8 μm at 50 mK in mesoscopic rings.
AB - Selective area growth is a promising technique to realize semiconductor-superconductor hybrid nanowire networks, potentially hosting topologically protected Majorana-based qubits. In some cases, however, such as the molecular beam epitaxy of InSb on InP or GaAs substrates, nucleation and selective growth conditions do not necessarily overlap. To overcome this challenge, we propose a metal-sown selective area growth (MS SAG) technique, which allows decoupling selective deposition and nucleation growth conditions by temporarily isolating these stages. It consists of three steps: (i) selective deposition of In droplets only inside the mask openings at relatively high temperatures favoring selectivity, (ii) nucleation of InSb under Sb flux from In droplets, which act as a reservoir of group III adatoms, done at relatively low temperatures, favoring nucleation of InSb, and (iii) homoepitaxy of InSb on top of the formed nucleation layer under a simultaneous supply of In and Sb fluxes at conditions favoring selectivity and high crystal quality. We demonstrate that complex InSb nanowire networks of high crystal and electrical quality can be achieved this way. We extract mobility values of 10000-25000 cm2 V-1 s-1 consistently from field-effect and Hall mobility measurements across single nanowire segments as well as wires with junctions. Moreover, we demonstrate ballistic transport in a 440 nm long channel in a single nanowire under a magnetic field below 1 T. We also extract a phase-coherent length of ∼8 μm at 50 mK in mesoscopic rings.
KW - droplet epitaxy
KW - InSb
KW - molecular beam epitaxy
KW - selective area growth
UR - http://www.scopus.com/inward/record.url?scp=85075429388&partnerID=8YFLogxK
U2 - 10.1021/acs.nanolett.9b04265
DO - 10.1021/acs.nanolett.9b04265
M3 - Article
AN - SCOPUS:85075429388
VL - 19
SP - 9102
EP - 9111
JO - Nano Letters: a journal dedicated to nanoscience and nanotechnology
JF - Nano Letters: a journal dedicated to nanoscience and nanotechnology
SN - 1530-6984
IS - 12
ER -