摘要
纳米结构单体组分分布的研究对基础研究及应用探索具有非常重要的意义。应用高分辨场发射俄歇电子能谱和扫描电子束对在550℃和640℃生长温度下分别沉积在硅单晶衬底上的纳米锗硅量子点结构的形貌和表面组分分布进行观察,结果表明:表层分布元素不是纯锗、硅或均匀单一的锗硅合金,而是不均匀分布的锗硅混合物。纳米结构内,元素呈不均匀分布,锗元素富集在中心部位。640℃生长温度下的相同形貌的纳米点结构显示不同的元素分布性质。组分分布的巨大差异是由不同温度下硅向锗中不均匀偏析所致。
High-resolution schottky field emission Auger electron spectroscpy （FE-AES） and scanning electron microscopy （ SEM ） were used to investigate the surface topography and distribution of the lateral composition of Ge QDs grown by nlolecular beam epitaxy on Si（001） substrate. Two types of samples grown at 550℃ and 640℃ were investigated respectively. Results demonstrate that the dot lateral composition is neither pure Ge nor Si nor homogeneous GexSi1- x, but the mixture of Si and Ge. The composition distribution is asymmetric in one dome-shaped dot, showed lower Ge concentration in the periphery part and higher Ge concentration in the center part. Domes grown at 640℃ show different composition distribution features even in same shaped domes. This noticeable difference can be attributed to the different degrees of Si alloying into the Ge QDs at different growth temperatures.
出处
《表面技术》
EI
CAS
CSCD
2008年第5期24-25,共2页
Surface Technology
