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

Abstract

A quartz crucible preparation device, including a sealed shell, a water-cooled mold, a graphite crucible, a first vacuum pump, a second vacuum pump, and an exhaust assembly, the bottom of the graphite crucible is embedded in a water-cooled mold, and the inlet of the first vacuum pump communicates with the inner cavity of the water-cooled mold , a first connection port is provided above the side wall of the sealed housing, a second connection port is provided below the side wall of the sealed housing, and the exhaust assembly includes a three-way joint, a first valve, a second valve, and a third valve , the first interface of the three-way joint is connected to the first connection port, the second interface of the three-way joint is connected to the inlet of the first valve, the outlet of the first valve is connected to the inlet of the second vacuum pump, the inlet of the second valve is connected to the three The third interface of the through joint is connected, the inlet of the third valve is connected with the second connection port, the sealed shell and the water-cooled mold are provided with an independent vacuum, which can meet the requirements of the dehydration process, and the hydroxyl content can be reduced to 20-30ppm. It also provides A method of reducing dehydroxylation in quartz crucibles.

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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