Electron Holography Characterization of Total Ionizing Dose Effects in Oxide–Nitride Stacks

In this work, an analysis of total ionizing dose (TID) effects in metal-nitride–oxide-semiconductors (MNOSs) was performed using electrical characterization and electron holography. Technology computer-aided design (TCAD) simulations were also performed to reproduce the holography findings. By matching the simulation results with electron holography data and capacitance-voltage (CV) measurement results, the distributions of holes and electrons in the nitride and oxide film are extracted. Close matching between the experimental data and simulation results establishes that charge buildup within the dielectric layers after irradiation can be directly imaged and quantified. Electron and hole trapping in the nitride layer near the SiO2/Si3N4 interface, identified using the holography measurements, is also shown to be consistent with models presented in previous studies.