Interfacial abruptness in axial Si/SiGe heterostructures in nanowires probed by scanning capacitance microscopy

摘要

Si/SiGe heterostructured nanowires (hNWs) were grown by catalyst mediated vapor-liquid-solid mechanism via chemical vapor deposition. As-grown hNWs were characterized by scanning electron microscopy, transmission electron microscopy, and scanning capacitance microscopy (SCM). All these techniques allow us to spatially delineate Si/SiGe and SiGe/Si heterojunctions and show an asymmetry in terms of abruptness between these two interfaces. Material SCM contrast in Si/Ge system is explained by a difference of native oxide quality.