We have demonstrated low temperature formation of b–FeSi₂ nanodots (NDs) over 10¹¹ cm^-2 in areal density on SiO₂ by exposing Fe–NDs to SiH₄ and characterization of their light emission properties. With an increase in the amount of SiH₄ exposure, stable PL observed in near–infrared region was increased by a factor of ~13. Note that, further increase in the amount of SiH₄ up to 1800 Pa·sec, the PL intensity is weakened slightly. The observed decrease in the PL intensity is attributable to selective growth of Si onto the NDs after the formation of b–FeSi₂ phase.