Quantitative Analysis of Surface Potential Fluctuation at MOS Interfaces Using Conductance Method

The surface potential fluctuation ($\sigma _{s}$), determined by broadening of conductance curves in the conductance method, is an interesting quantity because$\sigma _{s}$can be interpreted to be related to the total amount of MOS interface charges. Although the conductance method is widely used to evaluate interface state density, the quantitative relationship between$\sigma _{s}$and MOS interface charges has not been fully investigated yet. In this research, the relationship between$\sigma _{s}$and interface charges is quantitatively examined by utilizing interface charge generation by Fowler–Nordheim (FN) injection and is compared with a theoretical model. As a result, it has been experimentally verified that$\sigma _{s}$can be universally expressed as a function of an areal density of total interfacial charges with a specific power law relationship, which is 0.5. This result is well explained by the theoretical model.