Determination Method for Interface State Densities Adapted to Ultrathin Dielectrics

In this paper modified Terman method for determination of interface state densities, adapted for nanosized dielectrics has been applied to the case of Al-gated MIS structures containing ultrathin (2.56 nm to 5.15 nm thick) SiO2 dielectric layer. It has been demonstrated that modified Terman method is effective in precise determination of interface states density distributions for nannosized SiO2 dielectric SiO2 layers. Tails towards the band edges are not present when using this method. For all three samples a peak around 0.3 eV is observed. It corresponds to the first peak of the Pb defect. Second peak corresponding to the Pb defect cannot be clearly distinguished due to the presence of a peak related to Al gate.