USE OF SILICON OXYNITRIDE AS A GRAPHITE MOLD RELEASING COATING FOR THE GROWTH OF SHAPED MULTICRYSTALLINE SILICON-CRYSTALS

A new process of preparation of shaped multicrystalline silicon ingots in graphite molds based on the directional solidification technique i s reported. The mold has a coating of silicon oxynitride instead of mo re commonly used silicon nitride on the inner side of its walls. The c oating acts as a mold releasing layer and makes the mold reusable. It also enables to use of demountable molds made by assembling two or mor e parts together. It is expected that the repeatable use of molds made of graphite sheets will be able to promote a considerable savings in the production cost of multicrystalline silicon ingots in industrial p ractice.