Effect of FIB-modification of Si (111) surface on GaAs nanowire growth

The paper presents the results of experimental studies of GaAs nanowire growth on Si (111) substrate with Ga focused ion beam modified areas with different treatment doses. We observed a significant difference between the parameters of nanowires arrays formed on modified and unmodified areas. It is shown that changing the dose of Ga ions from 52 fC/µm² to 1×10⁴ fC/µm² allows to form nanowire arrays with a different set of parameters in a single technological cycle with a high selectivity. The possibility of regulating of the NW length in the range of 1−6 µm, the density in the range of 0−7.8 µm^-2, the diameter in the range of 28−95 nm and the normally oriented NWs in the range of 5−70% by focused ion beam have been experimentally demonstrated. The change of modes and mechanisms of the catalytic centers formation and the initial stage of GaAs NWs growth were revealed.