Current conduction and stability of CeO2/La2O 3 stacked gate dielectric

The current conduction behaviors in CeO₂/La₂O ₃ 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 (O_I) 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 O_I reduces and a negative charge built-up results which further reduces the leakage current and threshold voltage of p-channel metal-oxide-semiconductor transistors. © 2012 American Institute of Physics.