Crucible coating layer for polycrystal silicon or single crystal silicon and preparation method thereof

Abstract

The invention relates to a crucible coating layer and a preparation method thereof, in particular to a crucible coating layer for polycrystal silicon or single crystal silicon and a preparation method thereof, which are especially applicable to preparation of special-shaped and small-sized crucible coating layers for polycrystal silicon or single crystal silicon. The invention aims at providing the crucible coating layer for polycrystal silicon or single crystal silicon and the preparation method thereof, wherein the density range of the coating layer is 0.75-1.8g / cm<3>; the preparation method comprises the following operation steps that: silicon nitride powdery particles is adopted to be mixed with a solvent to obtain silicon nitride suspending liquid which is used as raw material for preparing the coating layer, wherein the silicon nitride suspending liquid is injected into a crucible; the silicon nitride suspending liquid is absorbed on the inner wall of the crucible; and the residual silicon nitride suspending liquid in the crucible is discharged. The coating layer provided by the invention has high strength, good density, and short needed time for preparation time, can utilize the silicon nitride powdery particles for preparing the coating layer completely and also improves the working environment for preparing the coating layer greatly and simultaneously.

Description

technical field [0001] The invention relates to a crucible coating and a preparation method thereof, in particular to a crucible coating for polycrystalline silicon or single crystal silicon and a preparation method thereof, especially suitable for the preparation of special-shaped and small-sized crucible coatings for polycrystalline silicon or single crystal silicon. Background technique [0002] At present, crucible coatings for polysilicon are generally prepared by spraying. Raw materials for preparing coatings generally refer to silicon nitride suspensions obtained by mixing silicon nitride powder particles with solvents. Due to the use of spraying methods to prepare crucible coatings for polycrystalline silicon or single crystal silicon, a large amount of nitrided silicon will be produced. Silicon dust, the working environment is poor, and the utilization rate of silicon nitride powder particles for coating is low, the required coating preparation time is long, and the...

AI Technical Summary

Problems solved by technology

Raw materials for preparing coatings generally refer to silicon nitride suspensions obtained by mixing silicon nitride powder particles with solvents. Due to the use of spraying methods to prepare crucible coatings for polycrystalline silicon or single crystal silicon, a large amount of nitrided silicon will be produced. Silicon dust, the working environment is poor, and the utilization rate of silicon nitride powder particles for coating is low, the required coating preparation time is long, and the production cycle is long

[0003] The strength of the coating prepared by spraying is low, which will cause bubbles and cracks in the coating. In severe cases, silicon liquid leakage will be caused during the process of preparing polycrystalline silicon or single crystal silicon, resulting in major economic losses. In addition, the coating prepared by spraying method is the accumulation of false particles, resulting in low density of the coating. When it is applied to the preparation of polycrystalline silicon or single crystal silicon, the sticky crucible phenomenon will occur, resulting in the cracking of the silicon ingot or the crucible Damaged, resulting in the inability to carry out the next slicing process or leakage of silicon liquid, resulting in significant economic losses

[0004] The prior art also includes the use of chemical vapor deposition, high-temperature flame treatment and other expensive and complicated means to prepare crucible coatings for polycrystalline silicon or monocrystalline silicon. Although the prepared crucible coatings have high density, the method is complicated to operate , the preparation cost is high, and it is difficult to popularize and apply in production