AlN晶体PVT生长装置的智能控制系统研究

Research of Intelligent Control System for AlN Crystal PVT Growth Device

AlN晶体的物理气相传输(PVT)法生长条件要求苛刻,如0.3~5 atm的高纯氮气生长气氛和2100~2400℃的生长温度。结合AlN晶体PVT生长工艺的特点,通过可编程逻辑控制器(PLC)进行适用于氮化铝(AlN)晶体PVT生长装置的智能控制系统的研究。首先,提出了倒置温场的生长工艺以降低AlN晶体PVT生长的成核数量,并通过自动控制程序设计满足不同生长阶段的温场要求;其次,针对设备可能存在超温、超压及冷却水断流等实验安全问题,设计并实现系统的自动化报警及自处理操作;最后,在实验操作上,实现AlN晶体生长的"一键式"全自动化工作。

The demanding growth conditions（ e. g. high purity nitrogen atmosphere of 0. 3-5 atm and high growth temperature of 2100-2400 ℃）,are one of the key challenges of physical vapour transport（ PVT）for growing Aluminum nitride（ AlN） crystals. Combining with the unique technologies of AlN crystal PVT growth,programmer logic controller（ PLC） was employed to establish a set of intelligent control system for AlN crystal growth. Firstly,the reverse temperature method is proposed to reduce the quantity of nucleation. Automatic control system is designed to realize the demands of different temperature in different stages. Secondly,we accomplish the automatic alarm and self-processing operations systems to solve potential safety hazards,such as excess temperature,excess pressure,cutoff of cooling water and so on. Finally,a unique user-friendly design of one-touch operation is fulfilled for AlN crystal growth.