Electrochemical and Solid-State Letters · 2009 · 32 citations · 18 references
EngineeringElectrical EngineeringMaterials ScienceMicroelectronicsSemiconductor DevicesSemiconductor MaterialsAmorphous Electronic MaterialsAmorphous SemiconductorsMetal-oxide-semiconductor Field-effect TransistorsSemiconductor Device MaterialsThin-film MaterialsThin-film TransistorsAmorphous Indium Gallium Zinc OxideBias Stress EffectsBias Stress InstabilityGate Oxide DegradationOrganic Light-emitting Diode DisplaysOxide Thin-film TransistorsReliability Degradation MechanismsTrapping Effects
The electrical instability in thin-film transistors (TFTs) based on amorphous indium–gallium–zinc oxide (a-IGZO) was investigated using constant bias and constant current stress. Stress conditions were chosen such that TFT is turned on, whereas the potential at the gate dielectric–a-IGZO interface is below the electron accumulation threshold. Drain current in this low bias regime is still sufficient for driving pixels in an organic light-emitting diode display (AMOLED). We found that the degradation is due to charge trapping near the a-IGZO–gate dielectric interface. The obtained results enabled a straightforward assessment of a-IGZO TFTs' instability for their application in AMOLEDs.
18