硅材料界面形态演化过程的相场法研究

Research on Interface Morphology Evolution Process of Silicon Materials Using Phase Field Method

采用有限差分法求解高界面能各向异性的相场模型,对硅材料晶粒生长过程进行模拟,分析了界面能各向异性强度和过冷度对界面形态演化的影响。结果表明:在高界面能各向异性下,硅晶粒为典型小平面枝晶形态,模拟结果和实验结果吻合。随着界面能各向异性强度的增大,晶粒界面形态由类球状经光滑枝晶向小平面枝晶转变;随着过冷度的增加,晶粒界面形态由类矩形向小平面枝晶转变。Y轴正方向晶粒长度在界面能各向异性强度为0.15和0.1时相当,Y轴正方向晶粒尖端温度在界面能各向异性强度为0.15时略高于界面能各向异性强度为0.1时的值。

The phase field model with strong interfacial energy anisotropies was used to simulate the grain growth of silicon material by finite difference method. The effects of the anisotropy strength of interface energy and undercooling on the evolution process of interface morphology were studied. The results show that the grain grows into facet dendrites with strong interfacial energy anisotropies, the simulation results match well with the experimental results.With the increase of interface energy anisotropy strength,the interface morphology of silicon grain changes from near-spherical shape to the facet dendrite morphology by smooth dendrite. With the increase of undercooling, the interface morphology of silicon grain turns from quasi-rectangular shape to the facet dendrite morphology. The size of grain in the direction of the positive Y-axis is equivalent when the anisotropy strength of interface energy is 0.15 and0.10. But the tip temperature of grain in this direction with the interface energy anisotropy strength value of 0.15 slightly is more than the value of 0.10.