Regensburg 2022 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 12: Quantum Dots and Wires 3: Growth
HL 12.4: Vortrag
Dienstag, 6. September 2022, 10:30–10:45, H32
Non-vapor-liquid-solid selective area epitaxy of GaAs1-xSbx nanowires on silicon — Akhil Ajay1, Hyowon Jeong1, •Haiting Yu1, Nitin Mukhundhan1, Tobias Schreitmüller1, Markus Döblinger2, and Gregor Koblmüller1 — 1Walter Schottky Institute & Physics Department Technical University of Munich, Garching, Germany — 2Ludwig-Maximilians-University, Munich, Germany
Epitaxial growth of semiconductor nanowires(NWs)is generally known to proceed via a vapor-liquid-solid(VLS). However,an absence of the liquid droplet would be ideal for III-V NW integration on Si and the exploration of atomically abrupt NW heterostructures.In this work,we report a novel non-VLS growth mechanism for the selective area growth of GaAs1-xSbx NWs on Si(111)substrates using molecular beam epitaxy.Non-VLS NWs are known to have many structural defects and poor aspect ratios.Surprisingly,we observe an increased axial growth and aspect ratio in these NWs by adding low concentrations of Sb.This also contrasts the commonly believed enhancement in radial growth for VLS growth claimed to be due to the surfactant effect of Sb.We report on realizing control over aspect ratio and yield by optimizing SiO2 mask hole diameter,growth time and growth temperature.In this process we observe a hitherto unreported dynamic growth rate that increases with time.We also investigate the initial growth of such non-VLS NWs forming inside the SiO2 mask opening,describing the facets and morphology.We also explore n-doping in these NWs with Si which also helps in realizing nearly unity yield and homogeneity.