Low-temperature aqueous route processed indium oxide thin-film transistors by NH ₃ plasma-assisted treatment

We propose a simple and inexpensivestrategy for fabricating aqueous route indium oxide thin-film transistors (In ₂ O ₃ -TFTs) at much lower annealing temperatures (T _a = 140 °C) using NH ₃ plasma-assisted treatment (PAT) process to In ₂ O ₃ film surfaces. During the NH3 PAT, the substrate temperature, plasma power, and gas flow were maintained at 140 °C, 50 W, and 100 sccm, respectively. The effect of a sequence of postannealing and PAT, namely, anneal after plasma (AAP)/anneal before plasma (ABP), was studied in detail. The results show that the NH ₃ PAT can promote the fracture of-OH, passivate the V _o , and increasethe conductivity of In ₂ O ₃ films at lowtemperatures. The AAP instead of ABP is a suitable method to realize high-performance low-temperature processed In ₂ O ₃ -TFTs on account of the higher oxidation degree, appropriate N doping, as well as more effectively H doping in AAP sample. The fabricated In ₂ O ₃ -TFTs based on AAP exhibited acceptable electrical performance of ∼1.3 cm ² /V · s mobility and ∼10 ⁷ on/off current ratio at low temperatures. The novel method for fabricating the In ₂ O ₃ -TFTs opens a way for the development of nontoxic, low-cost, and low-temperature oxide circuitry.