Growth of m-plane GaN quantum wires and quantum dots on m-plane 6H-SiC

Growth of m-plane GaN quantum nanostructures on an AlN buffer layer on m-plane SiC is investigated. GaN nanostructures with different shapes are obtained depending on the AlN buffer layer thickness and the amount of GaN deposited. For AlN buffer layer below 300 nm, GaN quantum wires, elongated perpendicularly to the c axis, are obtained independently of the amount of GaN deposited. For buffer layer thickness above 300 nm, and for an amount of GaN below (above) 5 ML (monolayer), GaN quantum dots (wires) are obtained. The difference in m-plane GaN morphology is related to the buffer layer stress state and to the anisotropic surface diffusion of m-plane GaN. Optical properties suggest an absence of internal quantum confined Stark effect. (C) 2007 American Institute of Physics.