| 초록 |
Epitaxial GaN films were grown by using a metal-organic chemical vapor deposition (MO-CVD) on sapphire substrate with AlN buffer layer. The AlN with different crystallinity were grown as a buffer layer by ex-situ sputter. The properties of the epitaxial GaN films were strongly influenced by the crystallinity of AlN buffer layer. The influence of AlN crystallinity on the surface morphology and roughness of GaN films was investigated by field-emission scanning electron microscope (FE-SEM) and atomic force microscope (AFM), respectively. The crystal quality of GaN films was evaluated by high-resolution X-ray diffraction (HR-XRD) with various scan mode. Dislocation densities of GaN films were estimated using full with half maximum (FWHM) values of diffraction peaks from HR-XRD. |
