Room-temperature fabrication of flexible gallium-doped zinc oxide thin-film transistors on plastic substrates

Bottom-gate-type oxide thin-film transistors (TFTs) on flexible plastic substrates have been fabricated, with Gallium-doped ZnO (GZO) by radio frequency (RF) sputtering as the channel material at room temperature. The devices use SiO2 as gate insulator and indium tin oxide (ITO) as gate, source and drain electrodes. To optimize performance of AZO TFTs, we studied effects of different oxygen/argon gas flow ratio on electrical properties of TFTs. We found that O2/Ar flow ratio influence the performance of GZO TFTs very significantly. Finally, we gained high performance GZO TFTs with excellent electrical properties, such as a drain current on/off ratio of 107, a subthreshold swing of 394mV/decade, a threshold voltage of 3.2V, and a field effect mobility of 20.7cm2/ V·s in saturation region.