Testing methodology for lifetime extrapolation of PZT capacitors

Wafer level reliability is a key tool for the development of new technologies, since it enables to anticipate the lifetime of these technologies in operating conditions. In this paper, we present a testing methodology for lifetime extrapolation of high density PZT capacitors. This study is related to a basic time-dependent dielectric breakdown characterization, from which we could identify several failure mechanisms, depending on the applied voltage stress level. The proposed testing methodology, based on cumulated voltage and temperature accelerations, enables to emulate only the relevant failure mechanism for lifetime extrapolation. Assuming an E model for voltage extrapolation and a top electrode perimeter scaling for geometry dependency, we finally developed a complete reliability model that takes into account the temperature, voltage and geometry influences on capacitors lifetime.