【摘要】 采用从头计算(abinitio)的方法对比研究了Si1-xGex合金半导体材料中W缺陷、CiCs缺陷和CiOi缺陷的性质。在Si1-xGex合金中,Ge原子不能与缺陷核心的C原子和O原子直接成键,但可能与W缺陷核心的间隙Si原子相连。在含CiOi缺陷的晶胞中,Ge原子倾向于取代沿[110]伸长方向的Si原子。随着合金中Ge含量的升高,W缺陷的形成能不断增加,结构稳定性逐渐降低。与W缺陷不同的是,CiCs缺陷和CiOi缺陷在不同Ge含量的Si1-xGex合金中形成能变化较小,变化幅度在0.15eV以内,理论研究结果与前人的实验结果相吻合。更多还原

【Abstract】 The characteristics of W defect,CiCs and CiOi defects in the Si1-xGex alloys were investigated using the ab initio method.In the Si1-xGex alloys,a direct Ge-C or Ge-O bond was unlikely to be formed,but the direct connection of Si and Ge in W center could not be excluded.In the Si1-xGex alloy containing CiOi defect,Ge atom was apt to substitute the Si atom in the [110] tensile direction.With the increase of Ge content in the Si1-xGex alloys,the formation energy of W defect increased rapidly,therefore the stability of W defect decreased.Different from W defect,the formation energy of CiCs and CiOi defects changed a little in the alloys with various Ge content,smaller than 0.15 eV.The theoretical calculation results were consistent with experimental results.更多还原