GaN epitaxial growth using RF pulsed laser deposition (PLD) method with molten Ga target

Epitaxial GaN thin films were grown on sapphire (0001) substrate by RF-pulsed laser deposition method with molten Ga target. A characteristic feature of this work is the flying-atom-energy control to get a suitable migration and to avoid the impinging damage during the growth. According to our ultra-fast plume observation, the mean drift energy of Ga plume was as high as 29 eV. By introducing the oblique incidence of the plume to the substrate surface, pretty good quality of GaN epitaxial films was obtained. The crystalline quality of GaN thin films was analyzed by conventional techniques, such as x-ray diffraction (XRD), reflection high energy electron diffraction (RHEED), scanning electron microscope (SEM) and photoluminescence (PL) measurements. The band edge emission (364 nm) was clearly observed in PL measurement at room temperature.