EVALUATION OF THE COULOMB ENERGY FOR SINGLE-ELECTRON INTERFACE TRAPPING IN SUB-MU-M METAL-OXIDE-SEMICONDUCTOR FIELD-EFFECT TRANSISTORS

Capture and emission time constants are measured for a set of individual interface traps in different metal-oxide-semiconductor field-effect transistors (MOSFETs) by random telegraph signals. The data are evaluated to extract the Coulomb energy induced by the transfer of a single electron into an interface trap. A unified Coulomb energy of the order of several hundred millivolts independent of trap-specific properties is found, which is proportional to temperature and decays logarithmically with inversion carrier density in the MOSFET channel. The Coulomb energy found is in quantitative agreement with the theoretical modeling. The Coulomb effect is large compared to the trap lowering by the electric field and to the residual entropy change.