大尺寸碳化硅单晶生长环境研究

Study on Growth Environment of Large Size SiC Single Crystal

摘要:

针对基于物理气相输运法的碳化硅(SiC)单晶生长系统,考虑对流换热的影响建立了传热与传质数学模型,并采用数值模拟的方法研究了其生长系统内的温度场与气相流场。研究表明:坩埚内温度、温度梯度以及加热效率随线圈匝间距与线圈直径的增加而逐渐降低。旋转坩埚可有效解决因线圈螺旋形状而导致的温度场不均匀性。通过不断调整线圈与坩埚之间的相对高度,可保证高品质晶体生长所需的最优温度场环境。此外,坩埚内径尺寸的增加,会加剧其内部自然对流效应。

Abstract:

Considering the influence of convective heat transfer, a mathematical model of heat and mass transfer was established for the growth system of large-size SiC single crystal based on physical vapor transport method. The distribution of temperature field and gas phase flow field in the growth system was studied by numerical simulation. The results show that the temperature, temperature gradient and heating efficiency in the crucible will gradually decrease with the increase of coil turn spacing and coil diameter. The rotating crucible can effectively solve the non-uniformity of temperature field caused by the coil spiral shape. By continuously adjusting the relative position between the coil and the crucible, the optimal temperature field environment for high quality crystal growth can be ensured. In addition, the increase of the inner diameter of the crucible will aggravate the natural convection effect.