4英寸VGFGaAs单晶生长的数值模拟与实验研究

Numerical Simulation and Experimental Study on 4″ VGF GaAs Crystal Growth

利用数值模拟和实验相结合的方法,研究了4英寸VGF GaAs单晶的生长。首先基于炉体结构和所采用材料,建立一个和真实单晶生长系统接近的炉体模型。根据此模型,采用晶体生长模拟软件CrysMas计算得到整个炉体内的温度分布、晶体及熔体的温度梯度、界面位置等。通过对单晶生长不同时间点的模拟,制定了一套单晶的生长工艺。然后,严格遵循此工艺进行单晶生长实验。通过对实验和模拟结果的对比分析,建立了实验和数值模拟之间的联系,为进一步利用数值模拟指导晶体的实际生长提供了依据。最后,利用数值模拟研究了单晶生长中"边界效应",探讨了晶体生长过程中产生多晶的原因。

The growth of 4＂GaAs crystal growth was studied by vertical gradient freezing （VGF） process with the aid of simulation and experiment. Firstly, a model-furnace was built, which based on the furnace structure and materials used. On the basis of the model, the distribution of temperature in the furnace, the gradient of temperature in melt and crystal, the position of interface were calculated with CrysMas special for simulation of the crystal growth. Moreover, a 4＂ VGF GaAs crystal growth process was established according to the simulation results at different time. Comparing experimental results with that of simulation, the relations of experiment and simulation were settled. Finally, the ＂interface effect＂ and the occurrence of polycrystalline during the VGF-GaAs crystal growth were discussed.