Ion-beam-assisted molecular-beam epitaxy: a method to deposit gallium nitride films with high crystalline quality

Abstract

Hexagonal gallium nitride has been deposited on 6H-SiC by low-energy-ion-beam-assisted molecular-beam epitaxy. X-Ray diffraction measurements indicate the high crystalline quality of the thin films. Cross-section transmission electron microscopy images prove that a two-dimensional growth mode is obtained with this technique in contrast to the columnar growth of gallium nitride, as it is known from other methods. Comparing the ion energy with the displacement energy of surface and bulk atoms, it can be understood that the ion bombardment enhances the surface mobility during growth but does not lead to defect generation.