Slurry for preparing polycrystalline silicon crucible coat and preparation method thereof

Abstract

The invention relates to slurry for preparing a polycrystalline silicon crucible coat in the field of semiconductors or photovoltaics, and also to a preparation method thereof. The slurry for preparing the polycrystalline silicon crucible coat comprises silicon nitride powder and a solvent, and is characterized in that: the silicon nitride powder is treated by an oxidant to form the silicon nitride powder of which the surface is coated with encapsulated silicon oxide. After the slurry for preparing the polycrystalline silicon crucible coat is coated on a crucible and baked, the silicon oxide and the silicon nitride form a combined layer with a higher strength, so that the crucible coat with a high antistrip performance is obtained; and meanwhile, the oxide in the slurry for preparing the polycrystalline silicon crucible coat avoids aggregation, can be uniformly coated on the surface of silicon nitride particles, has low oxygen content, and avoids the influences on the quality of a silicon ingot.

Description

Slurry for preparing polysilicon crucible coating and configuration method technical field The invention relates to a slurry for preparing a polysilicon crucible coating in the semiconductor or photovoltaic field, and also relates to a configuration method of the slurry. Background technique In polycrystalline silicon ingots, ceramic crucibles are usually used to hold molten silicon liquid. The main chemical component of the ceramic crucible is silicon dioxide. The reaction between molten silicon and silicon dioxide will generate volatile silicon monoxide and oxygen. Oxygen will directly enter the silicon melt and pollute the silicon. The silicon monoxide reacts with the graphite in the furnace to form silicon carbide and carbon monoxide, which reacts with the molten silicon to form more silicon monoxide and carbon, introducing carbon impurities into the silicon. In addition, silicon will also react with some impurities in the silica crucible, such as iron, boron, aluminu...

AI Technical Summary

Problems solved by technology

Inorganic binders are prone to agglomeration, require good dispersion, and require a long time for slurry preparation. At the same time, this method is easy to introduce pollution to the coating, which increases the content of oxygen or other impurities in the coating, which ultimately affects the quality of the silicon ingot. quality