Quartz crucible preparation device and method for reducing dehydroxylation in quartz crucible

Abstract

The invention provides a quartz crucible preparation device, which comprises a sealing shell, a water cooling mold, a graphite crucible, a first vacuum pump, a second vacuum pump and an exhaust assembly, wherein the bottom of the graphite crucible is embedded into the water cooling mold, the inlet of the first vacuum pump is communicated with the inner cavity of the water cooling mold, a first connecting port is formed in the upper portion of the side wall of the sealing shell, a second connecting port is arranged below the side wall of the sealing shell, the exhaust assembly comprises a three-way joint, a first valve, a second valve and a third valve, the first port of the three-way joint is connected with the first connecting port,the second port of the three-way joint is connected with the inlet of the first valve, the outlet of the first valve is connected with the inlet of the second vacuum pump, the inlet of the second valve is connected with the third port of the three-way joint, the inlet of the third valve is connected with the second connecting port, the sealing shell and the water cooling mold are provided with independent vacuum, the requirement of the dehydroxylation technological process can be met, and the hydroxyl content can be reduced to 20-30 ppm. The invention further provides a method for reducing dehydroxylation in the quartz crucible.

Description

technical field [0001] The invention relates to the technical field of quartz crucible production, in particular to a quartz crucible preparation device and a method for reducing dehydroxylation in the quartz crucible. Background technique [0002] At present, quartz crucibles are mainly melted by high-temperature arc method. The heating method adopts high-temperature arc heating, and the heating material is heated by graphite electrodes with high purity. Before the quartz crucible is melted, high-purity quartz sand needs to be poured into the inner surface of the rotating graphite crucible that can be tilted at any angle, and formed by centrifugation. Then rotate the graphite crucible to move under the graphite electrode and align it concentrically. Then start the power supply, put the graphite electrode on the top of the graphite crucible or the inner surface of the graphite crucible, and quickly discharge the arc to heat the high-purity quartz sand on the inner surface o...

AI Technical Summary

Problems solved by technology

[0003] However, in the prior art, the fluctuation of the hydroxyl group in the quartz crucible after melting is relatively large, and the hydroxyl group exists in the quartz crucible as loose silicon-oxygen bonds, which changes the structure and physical and chemical properties of the quartz crucible, reduces the viscosity of the quartz crucible, and makes the quartz crucible It is easy to deform during the crystal pulling process and cause accidents

At the same time, the loose silicon-oxygen bonds are prone to reverse reactions during the crystal pulling process, and the diffusion of hydroxyl groups affects the oxygen content of the ingot, the occurrence rate of pores and the fluctuation of the resistivity of the ingot, and the diffusion of hydroxyl groups is easy to cause tiny particles in the transparent layer of the quartz crucible. Bubbles expand and burst, and in the case of a large number, it will cause the crystal to be broken

The hydroxyl groups in the quartz crucible are affected by the gas-liquid inclusions in the raw materials on the one hand, and the temperature and humidity in the melting environment on the other, which makes the hydroxyl groups in the melted quartz crucible fluctuate greatly, making it difficult to control and remove

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