Thermal field balancing device of sapphire crystal growing furnace

Abstract

The invention discloses a thermal field balancing device of a sapphire crystal growing furnace. The thermal field balancing device of the sapphire crystal growing furnace comprises an upper reflecting screen arranged at the top of the sapphire crystal growing furnace, a lateral reflecting screen arranged at the periphery of the sapphire crystal growing furnace and a lower reflecting screen arranged at the bottom of the sapphire crystal growing furnace. The upper reflecting screen and the lower reflecting screen are matched with the lateral reflecting screen, so as to form a furnace body thermal field balancing device, reflection heat is utilized by adopting all-directional combination, a thermal field with balanced gradient is formed, deformation of the reflecting screens is small, appropriate temperature gradient is maintained, high-quality crystals are obtained by reasonably controlling temperature pulling, the grown sapphire crystals are large in size and stable in structure, purity of the crystals is more than or equal to 99.995%; crystal dislocation density is less than 1000 / cm<2>; half-width of a crystal X-ray double crystal rocking curve is less than 20'; the grown crystals can be used as an LED (light-emitting diode) substrate material.

Description

technical field [0001] The invention relates to a sapphire crystal growth device, in particular to a temperature field balance device for a sapphire crystal growth furnace. Background technique [0002] With the rapid development of the LED lighting industry, the market demand for sapphire crystal substrate materials will grow rapidly. Since the melting point of sapphire crystal is as high as 2050°C and the Mohs hardness is 9, second only to diamond, the crystal growth and processing technology is very difficult. Only a few countries in the world can prepare sapphire crystals that meet the quality and size requirements of the substrate. [0003] At present, the growth technologies of sapphire crystal mainly include flame method, pulling method, guided mode method, heat exchange method, Kyropoulos method, temperature gradient method and descending method growth technology. Flame grown sapphire crystals have serious body defects such as inlays and bubbles, which cannot meet t...

AI Technical Summary

Problems solved by technology

The sapphire crystal grown by the pulling method has the disadvantages of large thermal stress, high dislocation density, and low utilization rate; while the heat exchange method flows helium gas throughout the crystal growth stage, and has strict requirements on the accuracy of the temperature control device, so the cost is very high. high

The advantage of growing sapphire crystals by the guided mode method is that crystals of different shapes can be grown according to actual needs, but it is difficult to grow crystals with high optical quality

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