Selective-Area Growth of GaN Nanocolumns on Si(111) Substrates Using Nitrided Al Nanopatterns by RF-Plasma-Assisted Molecular-Beam Epitaxy

The selective-area growth of GaN nanocolumns using predeposited Al nanopatterns (a 300-nm-period triangular lattice of 85-nm-diameter Al nanodots) on Si(111) substrates by rf-plasma-assisted molecular-beam epitaxy (rf-MBE) was demonstrated. GaN nanocolumns were grown at the edge of each nitrided Al dot after nitridation, forming a nanotubular structure in the growth temperature range from 941 to 966 °C. The size fluctuation of the sidewall thickness in the nanotubular structure was less than that of the diameters of nanocolumns grown on the Si surface outside the nitrided Al nanopatterns. At a high growth temperature of 966 °C, nanocolumn growth on the Si surface was completely suppressed.