Si_(1-x)Ge_x薄膜Ge表面偏聚的Monte Carlo模型

Monte carlo modeling of Ge surface segreation in Si_(1-x) Ge_x thin films

目前已经有许多学者研究了用 UHV/CVD方法生长 Si1-x Gex 薄膜时 Ge在表面、次表面的偏聚。一种对这种实验结果的解释是由于化学原因 (例如氧化 )造成锗原子的化学势差 ,这种化学势差成为锗原子迁移产生锗偏聚的动力。本文通过应用一个简单的统计热力学模型 ,对在这种机理下产生的锗偏聚进行了研究。这种用 Monte Carlo方法建立的模型所得到的计算结果与实验结果相当吻合。

Many experimental results concerning Ge segreation in Si 1-x Ge x expitaxial thin films have been reported recently,especially the Ge enrichment in the surface or subsurface layer.In this paper,we demonstrate that a simple model based on the regular solution theory can explain the Ge enrichment in the surface or subsurface.The model using the Monte Carlo method can show excellent agreement with the experimental data.