Temperature dependent time-to-breakdown (TBD) of TiN/HfO2 n-channel MOS devices in inversion

Effect of temperature on time-to-breakdown (TBD) of n+-ringed n-channel MOS capacitors with atomic layer deposited TiN/HfO2 based gate stacks is studied. While interfacial layer (IL) growth condition and thickness varied the high-κ layer thickness and processing was unchanged. These devices were investigated by applying a constant voltage stress (CVS) in inversion (substrate injection) at room and elevated temperatures. For high electric fields (10–15 MV/cm) across IL, it is observed that TBD is thermally activated irrespective of IL condition. Activation energies (2–3 eV after correction), found from Arrhenius plots of TBD for different IL conditions, show good matches with those associated with field-driven thermochemical model of breakdown developed for SiO2.