Effects of vapor-annealed gate dielectric on the properties of zinc tin oxide transparent thin film transistors

We investigated the effects of vapor-annealed gate dielectrics on the mobility, threshold voltage, and other characteristics of bottom gate zinc tin oxide (ZTO) transparent thin film transistors (TTFTs). Here, Al2O3 films coated on dry oxidized Si wafers were annealed in a water vapor atmosphere before ZTO deposition and used as TTFT gate dielectrics. The vapor-annealed ZTO TTFTs exhibited 50% higher mobility than those that were not vapor annealed. This improvement in mobility is ascribed to the hydrogen passivation in the amorphous ZTO films