Applied Physics Letters · 2012 · 10 citations · 18 references
EngineeringElectrical EngineeringMaterials ScienceMicroelectronicsSemiconductor DevicesThin FilmsDevice ReliabilityMetal-oxide-semiconductor Field-effect TransistorsSemiconductor Device MaterialsSemiconductor ReliabilitySemiconductor Thin FilmsThin-film TransistorsBias Stress EffectsCmos ReliabilityOxide Thin-film TransistorsReliability Degradation MechanismsSaturationStress Engineering In Thin FilmsSurface Oxygen AdsorptionThreshold Voltage
The nitrogen ambient encapsulation (NAE) technique is introduced to improve the reliability issue for the amorphous InGaZnO (a-IGZO) thin-film transistors under positive gate bias stress (PGBS). For the NAE devices, the threshold voltage (Vth) shift is significantly decreased from 1.88 to 0.09 V and the reduction of saturation drain current is improved from 15.75 to 5.61 μA as compared to the bare a-IGZO counterparts after PGBS. These improvements are attributed to the suppression of negatively charged oxygen adsorption on the a-IGZO backsurface and thereby well maintain the channel potential of NAE devices, which in turn sustain the Vth during PGBS.
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