CHEMICAL ENGINEERING ANALYSIS AND CONTROL OF GROWTH PROCESS OF BULK SINGLE CRYSTALS FOR OPTO-ELECTRONICS DEVICES

本项目旨在为光电子器件的块状单晶生长奠定科学基础。对半导体和氧化物晶体的提拉过程进行了实验和数值分析，对气相传输现象进行了数值研究，提出了一种提高SiO_2传质速率的装置，数值分析了熔池中流体的流动和换热，揭示了外加磁场对控制熔体振荡流动的有效性。从实验和数值上分析了浮力和热毛细管力对化合物半导体熔体流动的影响。将热应力分析与位错动力学模型相结合，对半导体单晶中位错密度进行了预测，开发了射频加热直拉法生长氧化物晶体的全局分析程序。该程序已有效地用于优化加热炉的结构和操作。将得到的温度分布用于热应力分析和裂纹形成分析。测量了几种氧化物熔体的热物性。

This project aimed to establish scientific fundamentals of bulk single crystal growth for opto-electronics devices. Czochralski process for semiconductor and oxide crystals have been analyzed experimentally and numerically.Gas phase transport phenomena was numerically investigated and a device was proposed to increase mass transfer rate of SiO.Fluid flow and heat transfer in melt pool was numerically analyzed and the application of magnetic field was revealed effective to control the oscillatory melt flows. Effect of buoyancy and thermocapillary forces on melt flow of compound semiconductors was analyzed experimentally and numerically. Thermal stress analysis and dislocation kinetic model was combined to predict dislocation density in semiconductor single crystals.Global analysis code was developed for a RF heated Czochralski furnace for oxide crystal growth. The code has been effectively used to optimize the structure and operation of the furnace. The temperature distributions thus obtained was used to thermal-stress and crack formation analyzes. Thermo-physical properties of some oxide melts have been measured.