Current Transport Mechanism in High-k Cerium Oxide Gate Dielectrics Grown on Germanium Substrates

摘要

The current transport mechanism of Pt/CeO_2/p-Ge metal-oxide-semiconductor devices is investigated. The results are based on the analyses of gate current vs gate voltage curves at temperatures ranging from 295 to 375 K. At low to medium electric fields (__0.1 to 0.9 MV/cm) the main current conduction mechanism is Schottky emission, while Poole_Frankel conduction is the dominant mechanism at higher fields across the oxide (__1.2 to 2.1 MV/cm). The barrier height (φ_b) at the Pt/CeO_2 interface is found to be equal to 0.91 ± 0.02 eV, while the trap energy level (φ_t) responsible for the Poole_Frertkel conduction is estimated to be around 0.60 ± 0.03 eV.