Fabrication and Characterization of β-FeSi₂ Thin Films Prepared by PLD Method Using Nd: YAG Laser

Abstract

β-FeSi₂ thin films were grown on Si(111) substrates by pulsed laser deposition (PLD) method using Nd: YAG Laser (λ = 1064 nm, laser energy = 50 mJ, laser energy density = 1.65 J/cm², repetition frequency = 10 Hz). In the fabrication process, three targets of (a) Fe(5N), (b) FeSi₂(3N) and (c) Fe(5N) + FeSi₂(3N) were used. The β-FeSi₂ thin films having best properties of crystallinity were obtained in the case of (c), in which the first layer as the template was formed with the target of Fe(5N) and then, on top of that, the second layer was deposited with the target of FeSi₂(3N). At this time, it was found that by XRD measurement, the degree of crystallinity of the films of the case (c) in which the first layer was introduced as the template improved 1.4 times as much as compared with the case (a), and that by SEM and AFM observations, surface morphologies also improved. Moreover, it was found that by TEM obeservation, the β-FeSi₂ thin grew uniformly along the direction of (220) or (202) from the interface of the Si substrate and the film to the free surface and that by EDS analysis, the compositions of Fe and Si were uniformly distributed.