Crystal growth technology and crystal growth furnace

Abstract

The invention provides a crystal growth technology. The crystal growth technology comprises the following steps of a preparation process, a seeding process, a shoulder-expanding process, a constant-diameter growth process, and a cooling and annealing process. The shoulder-expanding process comprises that after the seeding process, a flow of a refrigerant fed to the bottom of a tungsten crucible is increased without a change of heating element power so that a diameter of a crystal is increased. The constant diameter growth process comprises that when a flow of the refrigerant reaches to a preset value, the heating element power is maintained for a second preset time; and through monitoring of a cooling rate of the bottom of the tungsten crucible, constant diameter growth of crystals is controlled. Through an infrared thermometer, a flow of a refrigerant and the power of a heating element are controlled and a change of a temperature of the bottom of the tungsten crucible is monitored. The invention also provides a crystal growth furnace. The crystal growth furnace comprises the heating element woven from a wolfram wire mesh, the tungsten crucible surrounded by the heating element, a heat-conducting support for supporting the bottom of the tungsten crucible, and the infrared thermometer used for controlling the power of the heating element and a flow of refrigerant gas and connected to the bottom of the tungsten crucible. The crystal growth technology and the crystal growth furnace reduce requirements on technologist's experiences. The crystal growth technology simplifies the existing crystal growth technology and is convenient for industrialization.

Description

technical field [0001] The invention relates to a crystal growth process and a crystal growth furnace used in the crystal growth process. Background technique [0002] The composition of sapphire is aluminum oxide (Al 2 o 3 ), because of its superior characteristics in chemistry, electricity, mechanics, optics, surface properties, thermodynamics and durability, it is widely used in infrared military devices, missiles, submarines, aerospace, satellite space technology, detection and high Preferred window for high power lasers etc. Sapphire substrate is currently the most commercialized and technologically mature product in the market. GaN-based LEDs based on sapphire are mainly used for solid-state lighting, backlight, etc., and have broad market prospects. At present, the sapphire crystal growth methods mainly include the pulling method, the Kyropoulos method, and the heat exchange method. [0003] Among the above methods, the Kyropoulos method can obtain high-quality an...

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Problems solved by technology

However, due to the process characteristics of the pulling method, the crystal size obtained is relati

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