What is a single crystal growth furnace
source:
English website | publish time:2025年01月03日
A single crystal growth furnace is an equipment used for growing single crystal materials. The following will provide a detailed introduction from the dimensions of its working principle, structural composition, and application fields:
1. Working principle
Czochralski method: Place polycrystalline material into a quartz crucible and heat it with a graphite heater to melt it. Fix the seed crystal on the seed crystal axis, insert it into the surface of the melt, wait for the seed crystal to fuse with the melt, slowly pull the seed crystal upwards while controlling the rotation speed of the seed crystal, and the crystal will grow at the lower end of the seed crystal. By controlling parameters such as pulling speed, temperature, and crucible rotation speed, crystal growth can be achieved. For example, the growth of single crystal silicon mostly uses the direct pulling method.
Zone melting method: using high-frequency induction heating coils to locally melt polycrystalline materials to form a melting zone. The melting zone slowly moves on the polycrystalline rod, and the melted part forms a single crystal during the solidification process. This method is mainly used to prepare high-purity semiconductor single crystals, such as germanium single crystals, silicon single crystals, etc.
2. Structural composition
Host part: including frame, furnace body, water-cooled valve seat, crystal lifting and rotating structure, crucible lifting and rotating structure, etc. The furnace body usually adopts a double-layer water-cooled structure to ensure the normal operation of the equipment at high temperatures; The crystal lifting and rotating structure and crucible lifting and rotating structure are used to control the movement of the crystal and crucible, correctly adjust the relative position between the seed crystal and the melt, as well as the growth and rotation speed of the crystal.
Heating system: Graphite heaters are generally used, which can generate high temperatures to melt polycrystalline materials. The heating power supply provides stable power to the heater, and the fully water-cooled power supply device is equipped with a high-frequency transformer to form a new generation of high-frequency switching power supply, which can improve the efficiency of energy conversion.
Vacuum system: composed of vacuum pump, vacuum pipeline, vacuum gauge, etc., used to extract air from the furnace, establish a vacuum environment, reduce the mixing of impurities, and correctly control the vacuum degree inside the furnace.
Gas control system: mainly controls the flow rate and pressure of inert gases (such as nitrogen, helium, argon, etc.), protects the melt and grown crystals from oxidation, and regulates the atmosphere inside the furnace.
Computer control system: using PLC and upper industrial tablet PC, equipped with large screen touch HMI human-machine interface, high pixel CCD diameter measurement ADC system, and independent intellectual property monitoring system, it can achieve automatic control of the entire process from vacuum pumping, leak detection, furnace pressure control, melting, crystal pulling, shoulder placement, equal diameter, finishing to shutdown.
3. Application Fields
Semiconductor industry: used for producing semiconductor single crystal materials such as silicon, germanium, gallium arsenide, etc. These single crystal materials are the basis for manufacturing semiconductor devices such as integrated circuits, transistors, diodes, solar cells, etc.
Optical field: Single crystal materials that can grow optical devices such as laser crystals, fiber crystals, liquid crystal substrates, and optical lenses, used in laser technology, optical communication, imaging technology, and other fields.
In the field of energy:single crystals are used to prepare inorganic materials such as ion battery materials, ceramic materials, and electronic ceramic materials. They have a wide range of applications in energy storage, high-temperature superconductivity, sensors, and other areas.
3. Model classification: There are two main naming methods for single crystal furnace models, one is named based on the feeding amount, such as models 120, 150, etc; Another type of naming is based on the diameter of the furnace chamber, such as 85 furnace, which refers to the diameter of the main furnace tube.