Selective fabrication of InGaN nanostructures by the focused ion beam/metalorganic chemical vapor deposition process

In the present article we report on the selective fabrication of InGaN nano structures on Si coated GaN/sapphire substrates using the focused ion beam (FIB)/metalorganic chemical vapor deposition (MOCVD) process. InGaN quantum dots and InGaN quantum wires have been fabricated. The process combines wi ndow openings in the Si mask layer with localized highly energetic Ga+ FIB irradiation, subsequent photo-assisted wet chemical etching in a solution o f KOH:H2O2 (3:1 by mole) and finally the growth of InGaN/GaN nanostructures using MOCVD. This technique proved to be efficient in realizing practicall y damage-free etching, hence preventing the deterioration of the nanostruct ure's crystal quality. The density, size, and positions of the nanostructur es could be well designed and controlled using the above process. Structura l characterization by transmission electron microscopy, atomic force micros copy observations, and optical investigation by cathodoluminescence were ca rried out. (C) 2000 American Institute of Physics. [S0021-8979(00)04403-0].