Evaluation of the Dielectric by Measuring Leakage Currents on Self-Built Capacitor-Like Devices

Abstract

In metal-insulator-silicon (MIS) structure, 100 Å Ta2O5 films are deposited on 1000 Å doped poly silicon as a bottom electrode layer, followed by 500 Å TiN metal as the top electrode [1]. The measured leakage currents as shown are either temperature dependent as the top electrode is negatively biased or temperature independent as the top electrode is positively biased. Therefore, the mechanism of current conduction is believed to be Fowler-Nordheim tunneling as the top electrode of the capacitor is positively biased. As for the top electrode is negatively biased, the temperature-dependent leakage currents satisfying reasonable arguments about dielectric constant suggest that the most probable conduction mechanism should be attributed to Poole-Frenkel emission.