Electrical Performance of Zinc Oxide Thin Films Transistors

Authors R. Ondo-Ndong, H. Essone-Obame, N. Koumba

Laboratoire Pluridisciplinaire des Sciences, Ecole Normale Supérieure, B.P 17009 Libreville, Gabon

Issue Volume 9, Year 2017, Number 6
Dates Received 15 August 2017; revised manuscript received 15 November 2017; published online 24 November 2017
Citation R. Ondo-Ndong, H. Essone-Obame, N. Koumba, J. Nano- Electron. Phys. 9 No 6, 06002 (2017)
DOI 10.21272/jnep.9(6).06002
PACS Number(s) 73.40. – c, 73.50. – h
Keywords Thin film transistors, Properties capacities, MIS (39) , ZnO (82) .
Annotation The capacitive properties and performance of ZnO (TFT) thin film transistors prepared at 100°C were studied. The ZnO thin films were deposited by rf magnetron sputtering on silicon substrates. The frequency dependence of the conductivity and the capacity of the ZnO thin films was studied in the frequency range from 5 kHz to 13 MHz. Shown that total conductivity increases with frequency and decreases with temperature. This shows that the thermally activated conduction mechanism maintains the correlated barrier of the charge carrier on the localized states as a function of the experimental data. Activation energy is in the range of literature. ZnO-based transistors (TFTs) show non-linearities in both the current voltage and the transfer characteristics which are explained due to the presence of trap states. These traps cause a reversible threshold voltage change as revealed by low frequency capacitance voltage measurements in metal insulating semiconductor (MIS) capacitors. Thermal degradation experiments in heterojunctions confirm the presence of a trap state at 0.32 eV.

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