Method for controlling the morphology of sapphire seeding by foaming method

Abstract

The invention discloses a method for controlling a sapphire seeding form of a Kyropoulos method. The method comprises that an aluminum oxide raw material is placed in a mono-crystal furnace crucible, seed crystal is installed on a seed crystal rod, a vacuum system and a heating system are started, the voltage of the heating system is adjusted, so that the aluminum oxide raw material is melted completely, a convectional stable state of a melt surface is achieved, and the deviation distance of a cold core of a liquid level and a geometric centre of the crucible is less than 20mm; the seed crystal position is adjusted slowly, then the seed crystal is close to the melt liquid surface gradually, simultaneously, the working voltage of the heating system is adjusted, and the melting of the seed crystal is avoided; preheating is performed for 30 minutes at a position of 2-5mm from the lower end portion of the seed crystal to the melt liquid surface; and the seed crystal is rotated through a traditional Czochralski process, the working voltage of the heating system is adjusted, the diameter of the end portion of crystallization is controlled to be less than 50mm and shouldering is started to be performed after the cold core is coated by the end portion of the crystallization. By the aid of the method, the form of the end portion of the crystallization can be well controlled, the operation is simple, and the success ratio and the yield of the seed crystal are improved.

Description

technical field [0001] The invention relates to a sapphire growth process, in particular to a kyropoulos sapphire seeding morphology control method, which belongs to the technical field of sapphire preparation. Background technique [0002] Sapphire crystal (commonly known as corundum) has high optical transmittance from vacuum, ultraviolet, visible, near-infrared to mid-infrared, high mechanical strength, and extremely low absorption coefficient. Sapphire crystal has high temperature resistance and good chemical stability. It is an excellent laser matrix material. It is a window material for various optical components and infrared military devices, satellite space technology, and high-intensity lasers. It is the most commonly used blue light semiconductor diode. Substrate materials for LEDs and diodes LD cover almost all substrate applications. At present, the growth methods of sapphire mainly include pulling method (Cz), guided mode method (EFG), Kyropoulos method (Ky), h...

AI Technical Summary

Problems solved by technology

At present, all the Kyropoulos sapphire single crystal furnaces in the world have not realized the automatic operation of seeding. The entire seeding process depends on the experience and operation level of the seeding engineer, and there is no unified quantitative standard and operating procedures.