Abstract
Interfacial reactions of iron thin films on silicon have been investigated by transmission electron microscopy. FeSi was found to form after 400 °C annealing. Small amount of Fe 3 Si was detected in samples annealed at 450 to 500 °C. β-FeSi 2 grains were predominant with a few FeSi grains remained in samples annealed at 600 °C. β-FeSi 2 was found to be the dominant phase, whereas α-FeSi 2 was predominant in samples annealed at 900-1100 °C in N 2 ambient and in vacuum, respectively. Two-step annealings were effective in promoting the growth and improving the quality of epitaxial FeSi 2 . More uniform growth of epitaxial FeSi 2 was observed for samples annealed in vacuum than those heat treated in N 2 ambient. The mechanisms of epitaxial growth and the influence of impurities on the interfacial reactions are discussed.