Control of properties and geometric characteristics of selectively formed GaAs nanowires within the FIB treatment area on Si(111)

In this paper we present the results of experimental studies on the selective formation of GaAs nanowire arrays on the Si(111) substrate surface and the control of their properties. It has been shown that pre-treatment of the Si(111)  surface with a native oxide layer by a focused Ga-ion beam with further low-temperature annealing and high-temperature growth allows the formation of selective GaAs nanowire arrays with a different set of parameters that can be  controlled by changing the dose of ion-beam treatment. We also demonstrated the possibility of obtaining arrays with a yield of vertically oriented nanowires at the level of almost 100% and very high density (up to 8 μm⁻²). At the  same time outside the modified areas, the formation of nanowires was almost completely suppressed. Moreover, based on Raman spectroscopy study we have found that our approach allows to obtain nanowire arrays with clear zinc-blende crystal phase in wide range of nanostructure sizes.