Low temperature growth of β-FeSi2 thin films on Si(100) by pulsed laser deposition

Iron disilicide thin films were prepared by pulsed laser deposition on Si(100) substrates using an FeSi2 alloy target. Polycrystal films of β-FeSi2 phase could be formed even at a substrate temperature of 20°C. In addition to the β-FeSi2 phase, the FeSi phase was observed for substrate temperatures between 400 and 600°C. This is attributed to the mobility enhancement of Si atoms. At a temperature higher than 700°C, the FeSi phase disappeared and β-FeSi2 single phase films having columnar structure were grown due to the mobility enhancement of both the Fe and Si atoms. For all films deposited at various substrate temperatures, the stoichmetry was constant in the depth direction. Thus, it is thought that Si atoms from the substrate hardly diffused into the film.