光电半导体材料辐照诱发微观缺陷的演化特性研究

基于分子动力学计算方法,运用LAMMPS程序模拟了Si, GaAs, 3C-SiC三种半导体材料中辐照引起的级联碰撞过程,并分析了晶体内微观缺陷的演化特性。模拟结果表明,级联碰撞会在晶体内部形成类似离位峰的结构,大多数空位缺陷聚集在损伤区域内部,而损伤区域外围分布的主要是间隙缺陷。通过对三种材料进行缺陷簇分析,发现Si中缺陷簇数量明显多于GaAs,缺陷簇最大尺寸达到了17个原子。此外,三种材料中的Frenkel对的数量变化过程大致相同,均呈现“上升,下降,稳定”的趋势,但3C-SiC中的缺陷数量要远小于Si和GaAs,表明3C-SiC具有更好的辐射抗性,其晶体结构在受到辐照后仍能保持相对稳定。

Characteristics of Defects Evolution in Photoelectric Semiconductor Materials Induced by Irradiation

Based on the Molecular Dynamics calculation method, the cascade collision process induced by Si, GaAs and 3C-SiC was simulated by using LAMMPS, and the evolution characteristics of the microscopic defects within the crystals were analyzed. The simulation results show that the cascade collision will form a structure similar to the displacement spike inside the crystal, and most of the vacancy defects gather inside the damage region, while the periphery of the damage region was mainly distributed with interstitial defects. Through clusters analysis in the three materials, it is found that the number and size of clusters in Si are more than that in GaAs, and the maximum size of the defect clusters reaches 17 atoms. Besides, the number of Frenkel pairs in the three materials changes in the same way, showing the trend of "rising, falling and stabilizing". However, the number of defects in 3C-SiC is much smaller than that in Si and GaAs, indicating that 3C-SiC has better radiation resistance and its crystal structure remains relatively stable after irradiation.