Large size sapphire crystal preparing technology and growing apparatus thereof

Abstract

The invention relates to a preparing technique and a growth device of a large-size sapphire crystal, and the preparing technique of the large-size sapphire crystal comprises the following steps: (1) aluminum sesquioxide with high purity that is weighted is filled into a molybdenum crucible pot, a stove is vacuumized until the atmospheric pressure inside the stove is less than 10<-3> Pa, and then protective gases are filled into the stove, and the stove pressure achieves minus 90 to plus 20 KPa; (2) raw materials are heated until complete melting is achieved, and heat is preserved for 3 to 5 hours; (3) seed crystals are lowered by 15 to 120mm under heat preservation, and then the molybdenum crucible pot is lowered by the height of the molybdenum crucible pot; (4) the temperature in the stove is decreased until 1600 to 1750 DEG C; (5) the molybdenum crucible pot is re-raised to a heating region, and heat is preserved for 100 to 150 hours and then the temperature is decreased slowly until room temperature. The preparing technique of the large-size sapphire crystal of the invention is characterized by simple device structure, low production cost, good preparing technique stability, reliable process, easier bubble elimination and high yield, and can cultivate the single sapphire crystal with large size, small dislocation density and high quality.

Description

technical field [0001] The invention relates to the field of crystal crystallization technology. Background technique [0002] Sapphire is widely used in GaN substrate materials for high-brightness LEDs, precision instrument bearings, substrate materials for large-scale integrated circuits SOI and SOS, special optical components, window materials for high-energy detection and high-power lasers, and high-voltage materials. At present, the growth methods that can grow large-size optical-grade sapphire crystals mainly include: heat exchange method, kyropoulos method, resistance heating temperature gradient method, and crucible drop method. However, the heat exchange method uses helium as the cooling gas, which is expensive and cannot directly grow crystals in the C-axis direction; the Kyropoulos method has poor process repeatability and high energy consumption; the resistance heating temperature gradient method has poor process repeatability and low yield. The induction heatin...

AI Technical Summary

Problems solved by technology

However, the heat exchange method uses helium as the cooling gas, which is expensive and cannot directly grow crystals in the C-axis direction; the Kyropoulos method has poor process repeatability and high energy consumption; the resistance heating temperature gradient method has poor process repeatability and low yield

Induction heating iridium crucible pulling method, large investment and high cost

The traditional crucible descent method has a limited range of temperature gradient adjustment, and it is difficult to provide the temperature gradient required for growing large-sized sapphire crystals. At the same time, the ability of the crystal to remove impurities and bubbles is low, there are many internal defects in the crystal, and the yield of the crystal is only about 50%.

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