Abstract
We report observations of unipolar recovery of dielectric breakdown in fully silicided NiSi-gate HfSiON-SiOx bilayer dielectric based high-kappa metal-insulator-semiconductor (MIS) gate stack, analogous to resistive switching in metal-insulator-metal (MIM) nonvolatile memory devices. The dependence of the recovery voltage on breakdown hardness and filament location is analyzed and the physics behind MIS recovery, governed by joule heating induced oxygen vacancy trap passivation, is explained using failure analysis and statistical investigations. The observed MIS recovery phenomenon can be a tool to design for reliability in novel metal gate high-kappa gate stacks.