${hbox{Ta}}_{2}{hbox{O}}_{5}$ ;stabilized sensor response;Surface morphology;Ta2O5;tantalum compounds;temperature 200 degC;temperature 293 K to 298 K;temperature annealing;Temperature sensors;">

Plastic Compatible Sputtered Ta2O5 Sensitive Layer for Oxide Semiconductor TFT Sensors

Branquinho, R., J. V. Pinto, T. Busani, P. Barquinha, L. Pereira, P. Viana Baptista, R. Martins, and E. Fortunato, "Plastic Compatible Sputtered Ta2O5 Sensitive Layer for Oxide Semiconductor TFT Sensors", Display Technology, Journal of, vol. 9, issue 9, pp. 723-728, 2013.


The effect of post-deposition annealing temperature on the pH sensitivity of room temperature RF sputtered Ta2O5 was investigated. Structural and morphological features of these films were analyzed before and after annealing at various temperatures. The deposited films are amorphous up to 600 °C and crystallize at 700 °C in an orthorhombic phase. Electrolyte-insulator-semiconductor (EIS) field effect based sensors with an amorphous Ta2O5 sensing layer showed pH sensitivity above 50 mV/pH. For sensors annealed above 200 °C pH sensitivity decreased with increasing temperature. Stabilized sensor response and maximum pH sensitivity was achieved after low temperature annealing at 200 °C, which is compatible with the use of polymeric substrates and application as sensitive layer in oxides TFT-based sensors.