Room temperature deposited indium zinc oxide thin film transistors

Depletion-mode indium zinc oxide (IZO) channel thin film transistors were fabricated on glass substrates from layers deposited at room temperature using rf magnetron sputtering. The threshold voltage was in the range from -5.5 to -6.5 V depending on gate dielectric (SiO2) thickness and the drain current on-to-off ratio was similar to 10(5). The maximum field effect mobility in the channel was similar to 4.5 cm(2) V-1 s(-1), lower than the Hall mobility of similar to 17 cm(2) V-1 s(-1) in the same layers, suggesting a strong influence of scattering due to trapped charges at the SiO2-IZO interface. The low deposition and processing temperatures make these devices suitable for applications requiring flexible substrates. (c) 2007 American Institute of Physics.