Interfacial reactions of 2-D periodic arrays of Ni metal dots on (0 0 1) Si

Abstract

The fabrication of 2-D periodic arrays of nickel metal dots using polystyrene (PS) nanosphere lithography and the interfacial reactions of the Ni dot arrays on (0 0 1) Si substrates after different heat treatments have been investigated. The epitaxial NiSi 2 was detected to start growing in samples after annealing at 300 °C. As the annealing temperature was increased to 350–800 °C, only epitaxial NiSi 2 nanodot arrays were observed to form. The results revealed that the formation of epitaxial NiSi 2 is more favorable for the Ni metal dot arrays samples. The shape of the epitaxial NiSi 2 nanodot was found to be inverse pyramidal and the size of the silicide nanodots was measured to diminish with annealing temperature. Furthermore, amorphous SiO x nanowire arrays and single-crystalline Si nanowires were found to form in samples after annealing at 900 and 1100 °C, respectively. The results present the exciting prospect that other nanoscale metal silicide dot and nanowire arrays could be grown on the sub-100 nm pre-patterned Si substrates using the PS nanosphere lithography technique.