Current conduction and stability of CeO2/La2O3 stacked gate dielectric

Abstract

The current conduction behaviors in CeO2/La2O3 stack are studied. We found that large amount of hole injection under large negative gate bias can give rise to the accumulation of neutral interstitial oxygen (OI) species which serve as acceptors and promotes the hole conduction in the La2O3 film. Whereas if the amount of hole injection is lower than that of the oxygen anions injected from the capping CeO2 layer under a sufficient large negative gate bias, the amount of OI reduces and a negative charge built-up results which further reduces the leakage current and threshold voltage of p-channel metal-oxide-semiconductor transistors.