GexSi1-x/Si中应变的会聚束电子衍射研究

介绍了会聚束电子衍射（ＣＢＥＤ）技术与计算机模拟相结合测定ＧｅｘＳｉ１－ｘ／Ｓｉ化学梯度层中应变分布的实验结果，提供了一种高空间分辨率，高灵敏度，且适用于任何材料系中微区晶格常数测定及应变分布研究的技术途径。

Study of the strain in GexSi1-x/Si by convergent beam electron diffraction

Convergent beam electron diffraction (CBED), combined by computer simulation, has been to be a powerful tool for the strain study, due to its high spatial resolution and high sensitivity. The local lattice parameters and the strain in the graded Ge x Si 1-x grown on Si buffer by molecular beam epitaxy(MBE) have been determined by the technique. The results indicate that lattice parameters and the strain in graded Ge x Si 1-x increase while Ge content, x value, increase from 0.05 to 0.35.The lattice of the whole graded layer is tetra-symmetry basically although some slight deformations have been observed from CBED) pattern around the interface between graded GeSi and the Si buffer.There are thread dislocations with density as high as 10 7 /cm 2 in the middle area of the graded layer, but fewer exist in the top, which is attributed to the distribution and relaxation of the strain in the material system.