Reliability Performances of BST Capacitors for Impedance Tuning Applications

STMicroelectronics recently developed a solution of integrated tunable capacitor based on BST material, which offers excellent RF performances, low power consumption and high linearity required in adaptive radiofrequency tuning applications. This paper focuses more particularly on the development of a predictive reliability model established from highly accelerated tests performed directly at wafer level on dedicated capacitor test structures. The validity of such model, representative of Time-Dependent Dielectric Breakdown (TDDB) failure mechanism, was confirmed by additional package level reliability tests, carried out on final product samples. The lifetime predictions provided by the model turn out to be perfectly compliant with RF tunable applications, considering typical mission profiles for such products.