Self-assembling GaN quantum dots on AlxGa1-xN surfaces using a surfactant

Nanoscale GaN quantum dots were fabricated on AlxGa1-xN layer surfaces via metalorganic chemical vapor deposition. In order to achieve a self-assembling dot structure, a two-dimensional growth mode (step flow) of GaN films on AlxGa1-xN (x=0-0.2) surfaces that is energetically commenced under the conventional growth conditions was intentionally modified into a three-dimensional mode by using a ''surfactant.'' The surfactant is believed to inhibit the GaN film from wetting the AlGaN surface due to the change in surface free energy. The resulting morphological structures of GaN dots were found to be sensitive to the doping rate of tetraethyl silane used as a surfactant, the Al content (x) of the AlxGa1-xN layer, and the growth temperature. A very intense photoluminescence emission was observed from the GaN dots embedded in the AlGaN layers. (C) 1996 American Institute of Physics.