Texture and epitaxy by ion beam assisted deposition of gallium nitride

Nitrogen ion beam assisted deposition of thin gallium nitride (GaN) films on c-plane sapphire was performed to examine the influence of hyperthermal ion irradiation on the growth and the structural properties of the films. Therefore, the ion-to-atom (I/A) ratio and the ion energy were varied. X-Ray diffraction (XRD) measurements show that GaN films are epitaxial, but an expanded phase is formed due to ion-induced damage. The crystalline quality of the films depends strongly on the beam parameters. To obtain high quality films low ion energies are required. Apart from this, pole figure measurements show that even with unadvantageous growth parameters the GaN films remain epitaxial.