Sequential phase formation by ion-induced epitaxy in fe-implanted si(001)

Ion-beam-induced epitaxial crystallization (IBIEC) of Fe-implanted Si(OO1) was studied by transmission electron microscopy and Rutherford backscattering spectrometry. For sufficiently high Fe doses, it was found that IBIEC at 320 °C results in sequential epitaxy of Fe silicide phases in Si, with a sequence of y-FeSi2, α-FeSi2 and βFeSi2 with increasing Fe concentration along the implantation profile. The critical concentrations for the y-a and α -β phase transitions were determined as ≈ 11 and 21 at. % Fe, respectively. The observed sequential phase formation can be correlated to the degree of lattice mismatch with the Si matrix and the stoichiometry of the silicide phases