Low-Temperature Fabrication of Solution-Processed InGaZnO Thin-Film Transistors

We report a novel method for fabricating solution-processed quaternary In-Ga-Zn-O (IGZO) thin-film transistors (TFTs) at low annealing temperature. The method is to spin coat such binary oxide layers as Ga
₂
O
₃
, ZnO and In
₂
O
₃
consecutively and then anneal the layers at 250 °C . Finally, due to vertical diffusion of the binary oxides, the IGZO film with a vertically gradient In, Ga, Zn distribution (defined as vd-IGZO) is obtained and used as the channel layer of TFT. Compared with conventional IGZO (con-IGZO) TFTs annealing at 380°C, the vd-IGZO TFTs have better electrical performances.