High quality β-FeSi_2 thin films prepared on silicon (100) by using pulsed laser ablation of Fe target

摘要

High quality β-FeSi_2 thin films have been fabricated on silicon (100) substrate by the pulsed laser deposition (PLD) technique with the Fe and sintered FeSi_2 targets. The crystalline quality and surface morphology of the samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy. These results indicate that the samples prepared with a Fe target can acquire a better crystalline quality and a smoother surface than those with a sintered FeSi_2 target. The reasons were discussed with subsurface superheating mechanism. The intrinsic PL spectrum attributed to the interband transition of β-FeSi_2 for all the samples was compared, showing that the film prepared with Fe target can acquire a good PL property by optimizing experimental parameters. It is suggested that sputtering Fe on Si substrate by the pulsed laser offers a cheap and convenient way to prepare the β-FeSi_2 thin films.