Growth and doping of GaN films and nanowires by reactive sputtering

Abstract

GaN based devices play an important role to the recent development of nanophotonics, nanosensoring, and spintronics. The GaN nanostructures used in these technologies are usually grown by molecular beam epitaxy or chemical vapor deposition. The development of the reactive sputtering technique is proposed in this project, as an alternative way to produce GaN films and nanowires (both pure and doped).The materials will be produced by sputtering of a Ga target in a plasma containing argon and nitrogen. The growth of nanowires requires low Ga pressures and relatively high substrate temperatures as compared to those used for the deposition of two-dimensional films. The doping will be carried out simply by placing small pieces of Mg and Mn onto the target.The structural characterization of the films and nanostructures will be performed by atomic force microscopy, scanning electron microscopy, and X-ray diffraction. The optical characterization includes photoluminescence, transmittance and reflectance in the ultraviolet, visible and infrared. Magnetization measurements as a function of the applied magnetic field and temperature will be made in doped films and nanowires.The aim of the project is to deepen the understanding of the nucleation process of GaN films and nanowires, enabling the growth by sputtering of materials with optical, electronic, and magnetic properties of interest.