Low-Temperature Aqueous Route Processed Indium Oxide Thin-Film Transistors by NH3 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 NH
₃
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 Vo, and increase the conductivity of In
₂
O
₃
films at low temperatures. 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 ~107 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.