RF, DC, and reliability characteristics of Ta2O5 MIM capacitors

We present here the fabrication, the characterization, the reliability and the modeling of MIM capacitors using Ta2O5 as a dielectric. Leakage current of 3 mA/cm2 at 4 MV/cm, a breakdown field (Ebd) of 5.2 MV/cm and a capacitance density of 0.83 fF/mum2 have been obtained. For high temperature, current instability has been observed and has been attributed to ionic diffusion in dielectric and follows the space-charge-limited theory. This phenomenon increases dramatically the TDDB (Time Dependent Dielectric Breakdown) which is a key aspect for our applications.