Influence of growth parameters on In-droplet-assisted growth of InAs nanowires on silicon

Ezekiel A Anyebe

doi:10.1007/s13204-017-0585-8

Ezekiel A Anyebe

Open Access

https://doi.org/10.1007/s13204-017-0585-8

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Abstract

The influence of growth parameters on the morphology and density of InAs nanowires (NWs) grown on bare Si substrates using Indium (In) droplets as catalyst is investigated. By tuning the growth temperature, V/III flux ratio, and growth rate, the diameter and yield of as-grown NWs were controllably manipulated. It is demonstrated that the In-droplet-assisted growth of InAs NWs can only be realized on bare Si within a relatively narrow growth window of 420–475 °C. Below 420 °C, NWs’ growth is kinetically limited, while the highest yield of vertically aligned NWs was obtained at ~450 °C. It is shown that In-catalyzed InAs NWs nucleation can only be realized on Si at highly As-rich conditions (V/III flux ratio >50), while the axial growth rate was found to be strongly dependent on the V/III flux ratio. The nucleation and axial growth of In-catalyzed InAs NWs are promoted by a low growth rate, while a high growth rate favors the formation of unwanted parasitic islands.

Highlights

Semiconducting nanowires (NWs) have been touted as promising building blocks for applications in photonics and electronic devices (Duan et al 2003; Tian et al 2007; Colinge et al 2010; Tomioka et al 2012; Wang et al 2014)Appl Nanosci (2017) 7:365–370(Krogstrup et al 2013; Heiss et al 2014), and performance of transistors and solar cells, respectively, have been shown to be strongly dependent on the NWs diameter.It is well established that the size and density of NWs can be controllably manipulated by tuning basic growth precursors (Anyebe et al 2017; Li et al 2017)
Despite the significant influence of In-rich conditions on the NWs geometry (Jung et al 2014; Zhang et al 2014) resulting from strong differences in adatom kinetics compared to other growth techniques, little is known about the influence of growth parameters on the morphology and yield of In-catalyzed InAs NWs with the few available reports limited to metal organic chemical vapor deposition (MOCVD) growth on GaAs (Forbes et al 2010) and InP (Zhang et al 2013) substrates
A further rise in growth temperature (GT) to 450 °C promoted a slight increase in vertical NWs yield to *4.78 9 108 cm-2, which sharply contrasts the complete absence of NWs growth between 440 and 450 °C in Au- (Tchernycheva et al 2007; Babu and Yoh 2011) and In-(Forbes et al 2010) catalyzed InAs NWs growth on InAs and GaAs substrates, respectively

Summary

Introduction

Semiconducting nanowires (NWs) have been touted as promising building blocks for applications in photonics and electronic devices (Duan et al 2003; Tian et al 2007; Colinge et al 2010; Tomioka et al 2012; Wang et al 2014)Appl Nanosci (2017) 7:365–370(Krogstrup et al 2013; Heiss et al 2014), and performance of transistors and solar cells, respectively, have been shown to be strongly dependent on the NWs diameter.It is well established that the size and density of NWs can be controllably manipulated by tuning basic growth precursors (Anyebe et al 2017; Li et al 2017). An investigation of the influence of growth parameters on In-droplet-assisted InAs NWs grown on Si would unravel the conditions for realizing optimal NWs with the highest density and aspect ratio as well as enable for the predictable and reproducible fabrication of high performance, and impurity-free nanoelectronic devices compatible with the CMOS technology.

Results

Conclusion