Thin Films of High‐k Oxides and ZnO for Transparent Electronic Devices

Oxide‐based thin‐film capacitors (TFCs), thin‐film transistors (TFTs), and sensor structures (including transparent ones) deposited on transparent substrates are investigated. All oxide elements in these structures are deposited by atomic layer deposition (ALD). Optimization of the ALD processes, which results in layers suitable for the above‐mentioned devices, is briefly described. In particular, we demonstrate advantageous properties of composite dielectrics consisting of pairs of Al2O3, HfO2, ZrO2, or TiO2. These composites are then used as gate dielectrics in TFC and TFT structures, with ZnO layers deposited as channel and gate layers. The structures are obtained at low temperatures (no more than 150°C), which enables their deposition on elastic, transparent substrates (polymers, foils).