运用分子动力学模拟的方法,采用LAMMPS程序模拟了六方晶格结构的4H-SiC材料辐照下级联碰撞过程。先建立4H-SiC晶体结构模型,再模拟了不同能量的初始碰撞原子(PKA)级联碰撞产生点缺陷的演化。模拟结果表明,总的点缺陷包括空位缺陷、间隙原子和反位缺陷,并以空位缺陷和间隙原子为主,给出空位缺陷与间隙原子的空间分布图；级联碰撞产生的空位缺陷数量与PKA能量成线性关系；空位缺陷与间隙原子的空间分布,特别是空位缺陷与间隙原子聚集区域,与PKA能量有密切关系。上述结果为分析4H-SiC基材电子器件在辐照环境下电学性质变化提供理论基础。

The molecular dynamics method is used to simulate the cascade collision of 4H-SiC material with hexagonal crystal structure by using LAMMPS code. 4H-SiC crystal structure model is established and the evolution of radiation-induced point defects by the collision cascade is simulated at different primary knock-on atom (PKA) energy and initial incident direction. The simulation results show that the total point defects include vacancy defects, interstitial atoms and antisite defects, giving priority to vacancy defects and interstitial. The space distribution of vacancy defects and interstitial atoms is given, in which the number of vacancy defects produced by cascade collision has linear relationship with PKA energy, the space distributions of vacancy defects and interstitial atoms, especially the gathered area of vacancy defects and interstitial atoms, has a close relationship with PKA energy. The above results provide a theoretical basis for the analysis of electrical properties change of electronic devices with 4H-SiC substrate under irradiation environment.