Growth of AlGaAs nanostructures on crystallized Al2O3 interlayers for semiconducting nanowire growth on glass substrate

Abstract

We report on the growth of nanowires and AlGaAs nanostructures on an amorphous glass substrate using the crystallization techniques of amorphous Al2O3 interlayers prepared by atomic layer deposition. On the planar Al2O3 interlayers on the glass substrates after the hydrogen annealing treatment at 975 °C in the reactor of metal–organic vapor phase epitaxy set-up, AlGaAs hexagonal nanopillars (or nanodisks) and tetrahedral nanostructures are formed in addition to AlGaAs polycrystals. Structural characterizations by X-ray diffraction analysis and transmission electron microscopy show that the growth of AlGaAs{111}A or B planes is predominant even on the glass substrates. Cross-sectional lattice images reveal that the crystallized γ-Al2O3 grains are formed in the planar Al2O3 interlayers after the hydrogen annealing treatment. We observe that the 〈111〉 direction of γ-Al2O3 crystal grains tends to be titled against the substrate surface in the crystallized Al2O3 interlayers. By using AlGaAs nanostructure buffers in combination with the crystallized Al2O3 interlayers, we realize the nanowire formation tilted on the glass substrates. No AlGaAs growth is observed on the glass substrates without any crystallized Al2O3 interlayers, nor GaAs growth on the crystallized Al2O3 interlayers on the glass substrates without any AlGaAs nanostructure buffers. It is important to introduce the AlGaAs nanostructure buffers and crystallized Al2O3 interlayers for the nanowire growth on an amorphous glass substrate.