A method for growing large-sized sapphire single crystal over 80kg

Abstract

The invention relates to a growing method for a large-size sapphire single crystal with weight of no less than 80kg. A main control stage of the sapphire single crystal growing process comprises a crystal seeding stage, a diameter enlarging stage, a shouder circuit reshaping stage, an equal-diameter growing stage, an ending and pulling stage and a cooling and annealing stage. During the diameter enlarging stage, the cooling speed is controlled, so that slow single crystal growth is ensured. The shouder circuit reshaping stage is performed when the single crystal grows to achieve the weight of 1.0-1.5kg, firstly the voltage is regulated up so as to enable the single crystal to stop growth; and further, rotating parameters are regulated, so that a seed crystal rotates at a certain speed. During the equal-diameter growing stage, the pull speed is reduced; further the cooling speed is quickened; and when the single crystal growth is about to be over, the cooling speed is quickened and simultaneously the crystal is rapidly lift up, so that the crystal is completely separated from a bottom residual fusant, and thus ending and pulling of the crystal are realized. The growing method is capable of reducing the defects in large-size sapphire single crystals and further greatly lowering the technical duration of single crystal growth. Furthermore, the growing process can be used for realizing automatic pulling, effectively avoiding crystals from being adhered to a pan, and reducing the possibility that a polycrystal is formed at the bottom, and is beneficial to growth of the high-quality and large-size sapphire single crystal.

Description

(1) Technical field [0001] The invention relates to a growth process of a large-size sapphire single crystal weighing more than 80 kg, in particular to a large-size sapphire single crystal growth process combining the advantages of the pulling method and the Kyropoulos method. (2) Background technology [0002] Sapphire single crystal has excellent optical, mechanical, chemical and electrical properties, and can work under harsh conditions close to 2000 °C. It is widely used as a window material for various optical components, infrared military devices, space vehicles and high-intensity lasers. And become the material of choice for semiconductor substrates for LEDs. [0003] With the development of the sapphire application market, especially the continuous expansion of the civilian market (such as mobile phone screens, watch mirrors, etc.), the demand for sapphire single crystals has also increased, and many industry-related companies have expanded their production. In the ...

AI Technical Summary

Problems solved by technology

[0007] Aiming at the main problems faced by the growth of large-size sapphire single crystals, the present invention is based on the original SAPMAC sapphire single crystal growth process, combined with the advantages of the pulling method, and redesigns to form a method that can solve the problem of large-size sapphire single crystal growth. A method for growing large-sized sapphire single crystals over 80kg in sticky pots, prone to polycrystals at the bottom, and many internal defects

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