光电半导体材料辐照诱发微观缺陷的演化特性研究

Characteristics of defects evolution in photoelectric semiconductor materials induced by irradiation

摘要:

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。

Abstract:

Based on the Molecular Dynamics calculation method, the collision cascades and defects evolution processes in Si, GaAs and 3C-SiC are simulated by using LAMMPS. The simulation results show that there is displacement spike formed by defects, which most vacancy defects gather inside the region, while interstitial defects are distributed outside. Through clusters analysis, it is found that the number and size of clusters in Si are more than that in GaAs. Besides, the change trend of the number of defects in the three semiconductor materials is "rising, falling and stable",