Sapphire crystal furnace kyropoulos bubble growth method ky growth equipment

Sapphire crystallization furnace is a device for growing high quality sapphire crystals using the Kyropoulos method (bubble method) technology. By precisely controlling the temperature, lifting speed and cooling conditions, the device can grow large size and low defect sapphire crystal in high temperature environment, which is widely used in LED, optical window, semiconductor substrate and other fields.

Sapphire crystal growth furnace is a sapphire single crystal growth equipment using resistance heating method, using the principle of bubble growth can grow up to 85-120 kg sapphire crystal. The vacuum chamber used for sapphire growth in the equipment adopts a vertical structure. The vacuum chamber, including the upper cover and the bottom plate, adopts a double-layer water cooling structure, and the upper cover can be opened.

Technical Parameter

Working principle

1. Melting stage: The raw material of high purity alumina (Al₂O₃) is put into the crucible and heated to more than 2050°C through a heating system (such as resistance heating or induction heating) to completely melt.

2. Seed crystal initiation: The sapphire seed crystal is immersed in the melt, and the melt begins to crystallize on the surface of the seed crystal by precisely controlling the temperature gradient and pulling speed.

3. Crystal growth: By slowly lifting the seed crystal and rotating the crucible, the crystal grows gradually along the direction of the seed crystal. At the same time, the optimized thermal field design ensures uniform temperature distribution during crystal growth and reduces defects.

4. Cooling and annealing: After the crystal growth is completed, the temperature is slowly reduced and the annealing process is carried out to release the internal stress and improve the crystal quality.

Product structure and characteristics

1. Heating system: The segmented heater (side heater and bottom heater) can independently control the temperature, optimize the melt flow and heat field distribution.

2. Heat insulation system: multi-layer heat insulation screen (such as tungsten reflection screen, graphite heat insulation screen), reduce heat loss, improve heat field uniformity.

3. Lifting and rotating system: high-precision lifting mechanism (lifting speed range: 0.05-10mm/h) and rotating mechanism to ensure stability and uniformity during crystal growth.

4. Cooling system: circulating water cooling system (seed rod and furnace body) to prevent local overheating, protect equipment and improve crystal quality.

5. Vacuum system: equipped with mechanical pump and diffusion pump to ensure that the vacuum degree in the furnace reaches 6.0×10⁻⁴Pa to reduce impurity pollution.

6. Control system: PLC+ touch screen control, support process parameters pre-storage and real-time monitoring, to achieve automatic operation.

Main advantage

1. High-quality crystal growth: By optimizing thermal field design and accurately controlling process parameters, sapphire crystals with low defects (dislocation density <1000/cm²) and high uniformity are grown.

2. Large size crystal: Support the growth of 85-120 kg large size sapphire crystal to meet industrial needs.

3. High yield: yield >75%, significantly reducing production costs.

4. Energy saving and high efficiency: The use of low-energy thermal field design and efficient heating system to reduce energy consumption.

5. Automatic operation: automatic control system, reduce the dependence on manual experience, operation training cycle only 2-3 months.

6. Modular design: Modular equipment structure, easy to maintain and upgrade.