High‐Performance Amorphous Multilayered ZnO‐SnO2 Heterostructure Thin‐Film Transistors: Fabrication and Characteristics

Multilayered ZnO‐SnO₂ heterostructure thin films consisting of ZnO and SnO₂ layers are produced by alternating the pulsed laser ablation of ZnO and SnO₂ targets, and their structural and field‐effect electronic transport properties are investigated as a function of the thickness of the ZnO and SnO₂ layers. The performance parameters of amorphous multilayered ZnO‐SnO₂ heterostructure thin‐film transistors (TFTs) are highly dependent on the thickness of the ZnO and SnO₂ layers. A highest electron mobility of 43 cm²/V·s, a low subthreshold swing of a 0.22 V/dec, a threshold voltage of 1 V, and a high drain current on‐to‐off ratio of 10¹⁰ are obtained for the amorphous multilayered ZnO(1.5 nm)‐SnO₂(1.5 nm) heterostructure TFTs, which is adequate for the operation of next‐generation microelectronic devices. These results are presumed to be due to the unique electronic structure of amorphous multilayered ZnO‐SnO₂ heterostructure film consisting of ZnO, SnO₂, and ZnO‐SnO₂ interface layers.