Microstructure of beta-FeSi2 buried layers synthesis by ion implantation

A buried layer of iron disilicide was synthesized by ion implantation in (111) Si p-type maintained at 500 degreesC using 195 keV Fe ions with a dose of 2 x 10(17) at./cm(2), followed by annealing in a N-2 atmosphere at 850 degreesC for 90 min. The investigation of the phase composition is carried out by Rutherford backscattering spectrometry (RBS), whereas the structural characterization is obtained by means of both X-ray diffraction (XRD) pole figure and cross-sectional transmission electron microscopy (XTEM). The precipitates favor epitaxial growth with respect to (111) Si planes with epitaxial relationships (220) beta-FeSi(2)parallel to(111) Si and/or (202) beta-FeSi(2)parallel to(111) Si. A mixture of beta-FeSi2 and alpha-FeSi2 Silicides is observed in the as-implanted state. After annealing of the samples at 1000 degreesC, the XRD pole figures show the transition from beta-phase to alpha-phase.