Analysis of Charge-Pumping Data for Identification of Dielectric Defects

We introduce a data analysis methodology for multifrequency charge-pumping (CP) measurements, which allows extracting both spatial and energy profiles of the CP-active traps in the gate dielectrics along with the defect energy characteristics. The analysis is based on the charge trapping/detrapping model accounting for carriers tunneling between the substrate and the oxide traps and multiphonon-assisted structural trap relaxation associated with charge carrier localization in the trap. Comparison of the spatial and energy trap distribution profiles obtained from CP data collected on a set of high-k dielectric gate stacks of different thicknesses facilitate the calibration of the model parameters. Extraction of the bulk trap characteristics, including trap ionization and relaxation energies, extends the utility of the CP technique from quantifying defect density toward identifying the nature of defects in the dielectric.