Characterization of Laser Ablated GaN/ZnO Bilayer on Si(111)

We have fabricated ZnO and GaN bilayers on silicon (111) wafers by laser ablation in order to develop the preparation techniques of multi-layer devices in optoelectronics. X-ray diffraction patterns showed the film was c-axis oriented vertical to the substrate plane. Scanning electron microscopic images indicated that the surface morphology was improved with increasing deposition temperature. E₁(TO) phonon modes of ZnO and GaN, as observed by infrared reflectance measurements, were clearly observed in such bilayers, giving evidence of the presence of GaN films. All these results confirm that the laser ablation method using inactivated N₂ flow and a solid-state target is a suitable approach to prepare high quality GaN films.