Multicrystalline silicon ingots were fabricated via the directional solidification method in a vacuum induction furnace using silicon nitride (Si3N4) as quartz crucible coating. The effect of Si3N4 coating on the impurity content, transference, and distribution in Si ingots was investigated. The results can be summarized as follows: The impurities contained in Si ingots, including Fe, Ca, Mn, Cu, P, and B, were found to decrease at varying degrees when the inner surface of the quartz crucible was coated with Si3N4. A mixed layer composted by Si3N4 and Si was observed on the surface of the Si ingot. This mixed layer provided microdefects for the nucleation of metallic impurities. The Fe and N contents in the Si/Si3N4 mixed layer changed with the same tendency, and FeSi2 particles formed on the Si/Si3N4 crystalline boundary. Both Fe and Ca precipitated in the SiC particles near the Si ingot/Si3N4-coating interface.