Temperature dependent time-to-breakdown (T_(BD)) of TiN/HfO_2 n-channel MOS devices in inversion

摘要

Effect of temperature on time-to-breakdown (T_(BD)) of n~+ -ringed n-channel MOS capacitors with atomic layer deposited TiN/HfO_2 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 T_(BD) is thermally activated irrespective of IL condition. Activation energies (2-3 eV after correction), found from Arrhenius plots of T_(BD) for different IL conditions, show good matches with those associated with field-driven ther-mochemical model of breakdown developed for SiO_2.