摘要
Schimmel腐蚀液腐蚀结合高倍光学显微镜观察发现 ,不同尺寸的掩膜窗内生长的 Si Ge外延层中的位错密度在整个外延层中从 Si Ge/Si界面到 Si Ge外延层表面由少到多 ,再由多到少明显地分成 3个区 .无掩膜窗限制的大面积区内的 Si Ge层则只呈现 2个区 .掩膜材料与掩膜窗尺寸不同 ,这 3个区的位错密度也不同 .掩膜形成过程中产生的应力对衬底晶格的影响 ,以及掩膜边界对衬底与外延层的影响是造成这种不同的根本原因 .
Schimmel solution etching combined with the high resolution micrography, it is found that the dislocation density of the SiGe alloy grown by MBE could be divided into three parts distinctly from SiGe/Si interface to the SiGe surface in the small windows of the SiO 2 film or Si 3Ni 4 film. Two parts could be seen in the large area of the SiGe alloy without film limited. The effect of the stress in the films on the Si substrate lattice, and the effect of the edges of the films on the Si substrate and the SiGe layer are responsible for the differences above.
出处
《物理实验》
北大核心
2003年第2期43-47,共5页
Physics Experimentation
