Autocatalytic MBE growth of GaAs nanowires on oxidized Si(100)

TL;DR

This study demonstrates the growth of GaAs nanowires on oxidized silicon substrates using molecular beam epitaxy, revealing their epitaxial relation and specific morphological characteristics.

Contribution

It introduces a method for autocatalytic MBE growth of GaAs nanowires on Si(100) with oxide, highlighting epitaxial contact via pinholes and nanowire morphology.

Findings

Nanowires up to 15 micrometers long

Epitaxial relation to Si substrate via pinholes

Ga nanodroplets observed at nanowire tips

Abstract

GaAs nanowires were grown by molecular beam epitaxy on Si(100) substrates covered with 5 nm SiO2. The growth was performed with As4 at low, close to stoichiometric, As4/Ga flux ratio, using Ga nanodroplets as catalyst. The nanowires are found to be in epitaxial relation to the Si substrate due to contact via pinholes through the SiO2 layer. The nanowires are up to 15 micrometers long and have diameters of about 100 nm, the catalyzing Ga nanodroplets are observed at their tops.