Molded sapphire crystal growth method and apparatus thereof

Abstract

The invention discloses a molded sapphire crystal growth method and an apparatus thereof. The apparatus comprises a crystal growth furnace, a heater, a crucible, an internal crucible and a weighing system; the internal crucible is arranged in the crucible, and a fine tube is arranged at the upper portion of the internal crucible, has a capillary effect and is used for obtaining a small interface higher than a free liquid level in order to realize seeding; the internal crucible is put on a sapphire material to guarantee the coaxiality of the fine tube on the internal crucible and seed crystals; the position of the fine tube is a cold heart position, and crystals begin to grow with the decrease of the temperature; and the crystal growth rate is accurately controlled by the weighing system, crystals are pulled after a melt in the internal crucible is almost crystallized, the melt at the upper portion of the internal crucible falls to the bottom of the crucible, and crystallization is continuously carried out. Cylinder-like sapphire crystals can be prepared through the method and the apparatus; grown crystals have the advantages of excellent quality, small stress, low dislocation density, and good crystal perfection and optic uniformity; and the method and the apparatus have the advantages of increase of the utilization rate of the sapphire material, processing program simplification and easy industrialization.

Description

technical field [0001] The invention belongs to the technical field of crystal growth, and relates to a method for growing crystals, in particular to a method for growing a shaped sapphire crystal; meanwhile, the invention also relates to a growing device for shaped sapphire crystals. 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 in the form of 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, the quality of ultra-high-brightness white / blue LEDs depends on the material quality of the GaN epitaxial layer (GaN), and the quality of the GaN epitaxial layer is closely related to the surface...

AI Technical Summary

Problems solved by technology

The advantages of the Kyropoulos method are: high quality (optical grade), low defect density; the disadvantages are: complex operation, low consistency, low yield, difficult to grow C-axis crystals, and low material utilization

In addition, the Kyropoulos seeding method is very difficult, and it takes a long time to learn to master it, and it has high requirements for operators.

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