Time dependent dielectric breakdown of amorphous ZrAlxOy high-k dielectric used in dynamic random access memory metal-insulator-metal capacitor

Reliability is of serious concern for high-k dielectrics used in advanced memory applications. In this study, the time dependent dielectric breakdown behavior is investigated for metal-insulator-metal capacitors with amorphous ZrAlxOy thin films as insulator and TiN as electrodes. Constant voltage stress measurements over seven orders of magnitude in time show that the power-law model is appropriate for lifetime extrapolation. The voltage acceleration parameter increases with decreasing temperature, and the thermal activation energy, Ea, increases with decreasing stress voltage, both translating to a gain in lifetime under product operation conditions.