Applied Physics Letters · 2009 · 181 citations · 19 references
EngineeringElectrical EngineeringMaterials ScienceMicroelectronicsSemiconductor DevicesThin FilmsAmorphous Electronic MaterialsAmorphous SemiconductorsSemiconductor Device MaterialsSemiconductor PhysicsSemiconductor Thin FilmsThin-film TransistorsAmorphous Oxide SemiconductorsAmorphous Semiconductor FilmsAmorphous Thin FilmsDeposition ProcessesDoping In Thin FilmsOhmic ContactsSilicon NitrideThin-film Semiconductors
A fabrication process of coplanar homojunction thin-film transistors (TFTs) is proposed for amorphous In–Ga–Zn–O (a-IGZO), which employs highly doped contact regions naturally formed by deposition of upper protection layers made of hydrogenated silicon nitride (SiNX:H). The direct deposition of SiNX:H reduced the resistivity of the semiconductive a-IGZO layer down to 6.2×10−3 Ω cm and formed a nearly ideal Ohmic contact with a low parasitic source-to-drain resistance of 34 Ω cm. Simple evaluation of field-effect mobilities (μsat) overestimated their values especially for short-channel TFTs, while the channel resistance method proved that μsat was almost constant at 9.5 cm2 V−1 s−1.
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