Applied Physics Letters · 2013 · 17 citations · 13 references
EngineeringElectrical EngineeringMaterials ScienceMicroelectronicsSemiconductor DevicesSemiconductor MaterialsAmorphous SemiconductorsDevice SimulationMetal-oxide-semiconductor Field-effect TransistorsSemiconductor PhysicsSemiconductor ReliabilityThin-film TransistorsBias Stress EffectsBias Stress InstabilityDensity Of StatesSchottky Barrier CharacteristicsSub-threshold OperationSubthreshold SwingSubthreshold Swing AnalysisSubthreshold Swing Degradation
Instability mechanism of amorphous InGaZnO thin-film transistors under negative bias stress (NBS) was investigated. After strong NBS stress, we observed a negligible change in the subthreshold swing which is strongly dependent on the subgap density-of-states (DOS). On the other hand, there was substantial increase in the drain current at above-threshold operation. Therefore, the dominant mechanism of the NBS-induced instability is investigated not to be a change in the subgap DOS but a change in the parasitic resistance caused by the reduced Schottky barrier of the metal contacts. This was verified by the extracted source/drain resistance and Technology Computer-Aided Design simulation.
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Trap densities in amorphous-InGaZnO4 thin-film transistors
Mutsumi Kimura, Takashi Nakanishi, Kenji Nomura et al. · Applied Physics Letters · 2008 · 317 citations