Development of Simplified Simulation Method of Diffusion Based on Monte Carlo Analysis

大规模集成电路中导体等微元器件的失效主要是由原子尺度缺陷引起的。缺陷的形核通常是通过沿边界扩散进行的。然而，分子动力学模拟不能应用于实际组分的过程，因为它可以在很短的时间内模拟原子的行为。提出了一种模拟长周期缺陷形核过程的蒙特卡罗方法，重点研究了原子沿表面的跃迁。本文从原子力学的角度分析了铝导体中晶界沟槽的形核过程。用该方法成功地模拟了沟槽的形成过程。然后，用分子动力学方法模拟了原子在熔化温度附近晶界和表面交点附近的运动，并对低Sigma晶界进行了刻槽识别。分子动力学结果验证了新方法的有效性。

The failure of microelement such as conductors in a LSI is caused mostly by the atomic scale defects. The defect mucleation often takes place by diffusion along boundaries. The molecular dynamics simulation, however, can not be applied to the process in a real component because it can simulate the behavior of atoms in a very short period. A Monte Carlo method to simulate the process of defect nucleation in a longer period is proposed focusing on the jumps of atoms along the surface. In this study, the nucleation process of grain boundary grooving in an aluminum conductor is analyzed in terms of atomic mechanics. The formation of grooving is successfully simulated by the method. Then, the motion of atoms near an intersection between grain boundary and surface near the melting temperature is simulated by a molecular dynamics and the formation of grooving can be recognized for low SIGMA boundaries. The validity of new method is examined by the molecular dynamics result.