Atomic layer deposition of multicomponent amorphous oxide semiconductors with sequential dosing of metal precursors

Atomic layer deposition (ALD) is a suitable method for depositing amorphous oxide semiconductors (AOSs) because it has the potential for achieving high performance in complex structures owing to its excellent step coverage and atomic-scale controllability. Multicomponent AOSs are typically deposited using the ALD with a super-cycle method. In this study, multicomponent AOSs, i.e., IZO, ITO, and ITZO, were deposited using ALD by employing a sequential dosing of metal precursors. Their compositions were adjusted by varying the dose time of the indium precursor. Subsequently, we applied the IZO, ITO, and ITZO films in thin-film transistors (TFTs), which demonstrated normal transfer characteristics. The TFT containing ITZO with 73.9 at% indium exhibited a turn-on voltage of −1.01 V, subthreshold swing of 0.09 V/dec, and field-effect mobility of 35.9 cm2/(V s).