Dielectric Relaxation, Aging and Recovery in High-K MIM Capacitors

摘要

High-K metal-insulator-metal capacitors are used in many high-performance applications that require both excellent energy storage and minimal energy loss. Often the increase in dielectric permittivity is coupled with an increase in dielectric relaxation or absorption. Additionally, scaling demands that the devices often be used at higher fields, leading to the need to characterize the impact of voltage stress. In this work, the impact of temperature and constant voltage stress on dielectric relaxation in Al2O3 MIM capacitors is studied using measurements of the complex permittivity as a function of frequency and time with a measure-stress-measure program. We observe both the degradation of loss parameters extracted from these spectra and the slow recovery over time. We postulate the existence of a potential threshold of temperature acceleration, and a state of permanent irreversible degradation.