High quality β-FeSi2 thin films prepared on silicon (100) by using pulsed laser ablation of Fe target

High quality β-FeSi2 thin films have been fabricated on silicon (100) substrate by the pulsed laser deposition (PLD) technique with the Fe and sintered FeSi2 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 FeSi2 target. The reasons were discussed with subsurface superheating mechanism. The intrinsic PL spectrum attributed to the interband transition of β-FeSi2 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-FeSi2 thin films.