Formation of Si_2N_2O Microcrystalline Precipitates near the Quartz Crucible Wall Coated with Silicon Nitride in Cast-Grown Silicon

摘要

The chemical reaction near the crucible wall during directional solidification of Si crystals for solar cells has been investigated.Fragments of the crucible that were used for the crystal growth of a Si ingot were examined.As results, we found that a chemical reaction took place at the coating/ crucible interface and that silicon oxynitride particles precipitated near the crucible wall.The oxynitride precipitates were determined as stoichiometric Si_2N_2O and were revealed not to be amorphous but of orthorhombic crystal symmetry.We show crucial evidence of the formation of stoichiometric Si_2N_2O microcrystalline precipitates inside the Si crystal.