Au-catalyst-free epitaxy of InAs nanowires

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

“…At a high temperature of 475°C, only a slight decrease in NWs yield was observed, which is attributed to a long adatom diffusion length consistent with previous reports of InAs NW (Dayeh et al 2007). It is also likely that some of the predeposited In droplets are desorbed from the substrates at such high temperatures leading to the nucleation of fewer NWs (Forbes et al 2010). This indicates the strong influence of G T on NWs nucleation probability on Si.…”

“…An increase in growth temperature (G T ) to 420°C resulted in the growth of NWs with an estimated number density of *9.23 9 10 7 cm -2 . A further rise in G T to 450°C promoted a slight increase in vertical NWs yield to *4.78 9 10 8 cm -2 , which sharply contrasts the complete absence of NWs growth between 440 and 450°C in Au- Babu and Yoh 2011) and In- (Forbes et al 2010) catalyzed InAs NWs growth on InAs and GaAs substrates, respectively. Significantly, compared to the temperature-dependent NWs tapering observed in Au-assisted ) NWs, all the NWs are vertically aligned with uniform diameter along the growth axis independent of growth temperature.…”

“…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. However, despite the significant influence of In-rich conditions (and in effect the predeposition of In droplets) 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. Given the significant differences (Cho and Arthur 1975;Finnie and Homma 1999;Arthur 2002;Dubrovskii et al 2005;Koblmüller et al 2010) between MOCVD and MBE, it is essential to undertake a growth parameter study of MBE grown In-droplet-assisted InAs NWs on Si.…”

Self-catalyzed growth mechanism of InAs nanowires and growth of InAs/GaSb heterostructured nanowires on Si substrates

“…In droplets on the top of NWs will be consumed during such long time [20,30,42]. In droplets can be visible ex situ on the top of the InAs NWs grown at the lower temperature due to its short cool-down time, for example, the NWs grown at 360 1C [27,28]. Secondly, the V/III ratio and the flow of group-V precursor can directly affect the preservation of In droplets [27].…”

“…By summarizing the relevant reports, it is clear that In droplet catalyzes the growth of InAs NW via VLS mechanism at a growth window of lower temperature (320 1C-400 1C) and lower V/III ratio (LL) [27,28]. However, at a high temperature range from 500 1C to 600 1C, which is the most common growth window for InAs NW growth [19,20,29], the growth mechanism is still an open question and controversy.…”