Sapphire crystal growth method and special crystal growth equipment

Abstract

The invention relates to a sapphire crystal nucleation method and special nucleation equipment used for the sapphire crystal nucleation method. The method comprises the following steps: after melting of a raw material, the bottom end of a die is arranged in a melt, a-direction or m-direction seed crystals are lowered to the cold cores in the centers of a crucible and the die, seeding is carried out through the kyropoulos method, the temperature gradient in the vertical direction is utilized to enable the crystals to grow downwards from the center of the die, a seed crystal rod is slowly pulled, and meanwhile, the raw material is unceasingly added into a gap between the die and the crucible till the seed crystal rod reaches the pulling limit. Through adopting reasonable process steps and various parameters and adding the die with an auxiliary heater on the outer surface into the crucible, the crystals in the die are not adhered to the die; the die limits the crystal growth shapes, the effective utilization ratio of the crystals is remarkably improved to more than 60%; finally, the seed crystal rod is unceasingly pulled during equal-diameter growth, and the raw material is added between the die and the crucible, so that a continuous production effect is achieved.

Description

technical field [0001] The invention relates to a sapphire crystal growth method, and also relates to a special crystal growth equipment used in the sapphire crystal growth method. Background technique [0002] The composition of sapphire is aluminum oxide (Al 2 o 3 ), which is composed of three oxygen atoms and two aluminum atoms combined by covalent bonds, and its crystal structure is a hexagonal lattice structure. Because sapphire has the characteristics of high sound velocity, high temperature resistance, corrosion resistance, high hardness, high light transmission, and high melting point (2045°C), it is often used as a material for optoelectronic components. At present, sapphire substrate is a key material in the LED field, and its large size, high quality, and high utilization rate have become difficulties and goals for the development of the industry. [0003] There are many methods for the growth of sapphire crystal materials, mainly including: Kyropoulos method (...

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Problems solved by technology

[0004] The traditional Kyropoulos growing sapphire crystal usually uses a-direction seed crystals to grow crystals in a circular crucible, and the resulting crystals are mostly pear-shaped. When processed into c-direction wafers for substrates in the LED field, the utilization rate of the crystals is very low. Only about 30%, it is difficult to make a profit

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