Taking advantage of the eutectic points of Au/Sb and Au/Si at low temperatures, silicon nanocrystals doped with Sb atoms are fabricated on the surface of silicon wafers after an alloying reaction around 400 ℃. Scanning electron microscopy demonstrates that there exist craters in the shape of an inverted pyramid and large amount of nanostructures inside craters on the wafer surface due to Au/Si alloying reactions. Raman scattering spectroscopy verifies that these nanograins largely possess a crystal-like lattice structure. Secondary ion mass spectroscopy reveals that the doping concentration of Sb in Si exceeds 2×10¹⁸ cm^-3, surpassing the solid solubility of Sb in the bulk silicon crystal. This growth method is easy to implement with a low thermal budget, which potentially provides it the good compatibility with other micro/nano fabrication processes.