Enhanced solid phase growth of β-FeSi2 by ion-beam irradiation

Effects of ion-beam irradiation on solid phase growth of β-FeSi2 were investigated. Fe(10nm)/c-Si structures were irradiated with 20 keV Ar+ (5.0x1015 cm-2) at 25 or 400degC, and subsequently annealed at 800degC. X-ray diffraction (XRD) measurements showed that β-FeSi2 was formed after annealing at 800degC, and the formation rate was the fastest for the sample irradiated at 25degC. However, Auger electron spectroscopy (AES) results indicated that atomic mixing at the Fe(10 nm)/Si interface before annealing was the largest for the sample irradiated at 400degC. These results are discussed on the basis of the pre-amorphization of Si substrate, in addition to atomic mixing, which enhanced the solid phase growth of β-FeSi2 during subsequent annealing. (author)