Investigation of charge trapping in a SiO2/Si system with a scanning capacitance microscope

The local electrical properties of a SiO2/Si structure is investigated using a scanning capacitance microscope (SCaM). The sample investigated in this study was p-type Si with a 10-nm-thick thermal oxide layer. The capacitance measurement reveals the local variation of capacitance, which reflects the electrical properties of the Si substrate, SiO2/Si interface and SiO2 layer. We have injected charge into the SiO2/Si sample. The local variation and time evolution of the stored charge is clearly detected in a nondestructive manner by the SCaM.