Temperature-dependent degradation mechanisms of threshold voltage in La2O3-gated n-channel metal-oxide-semiconductor field-effect transistors

Metal-oxide-semiconductor capacitors and n-channel metal-oxide-semiconductor field-effect transistors with La2O3 gate dielectric were fabricated. The positive bias temperature instability was studied. The degradation of threshold voltage (Delta VT) showed an exponential dependence on the stress time in the temperature range from 25 to 75 degrees C. The degradation of subthreshold slope (Delta S) and gate leakage (I-G) with stress voltage was also measured. The degradation of V-T is attributed to the oxide trap charges Q(ot). The extracted activation energy of 0.2 eV is related to a degradation dominated by the release of atomic hydrogen in La2O3 thin films. (C) 2010 American Institute of Physics. [doi:10.1063/1.3482057]