Three-dimensional GaN nano-structure fabrication by focused ion beam chemical vapor deposition

We have demonstrated a position controlled GaN nano-structure fabrication by ion beam mediated growth methods. For this fabrication, we used two different methods. One is the "droplet epitaxy" which is a micro-crystal growth from Ga droplet followed by nitridation. By this method, the GaN micro-crystals in about 800 nm were found to be grown and cathode luminescence in broad wavelength (400-600 nm) were observed. Another one is the focused ion beam assisted chemical vapor deposition. Ga precursor gas and atomic N radicals impinged onto the surface simultaneously during the irradiation. By this method, the GaN nano-crystals of 200 nm × 100 nm block with 50 nm height was fabricated and strong near-band edge emission at 3.37 eV from GaN were observed. From the obtained results, ion beam assisted chemical vapor deposition proved to be a promising method to make GaN nano-crystal arrays.