Abstract
Thermal stability of polycrystalline NiSi 2 on high-dose BF + 2 -, Si + -, B + -, F + -, As + -, and P + -implanted (001) Si has been studied by both cross-sectional and plan-view transmission electron microscopy as well as by sheet resistance measurements. The surface coverage and grain size of polycrystalline NiSi 2 were found to be significantly influenced by the implantation species in silicon substrate. In Si + -, B + -, As + -, and P + -implanted samples, agglomeration of NiSi 2 became very severe after 800°C, 1-h annealing. The average grain sizes were larger than 0.5 μm. In contrast, almost full surface coverage was found in F + - and BF + 2 -implanted samples after 900°C, 1-h annealing. The growth of laterally uniform NiSi 2 and resistance to agglomeration at high temperatures in BF + 2 - and F + -implanted samples are attributed to the retardation of the growth of NiSi 2 grains by the presence of fluorine bubbles at the grain boundaries. Sheet resistance data were found to correlate well with the morphological and microstructural observation.