Top-gate Zinc Oxide Research Articles

Highly Stable Atomic Layer Deposited Zinc Oxide Thin-Film Transistors Incorporating Triple O2Annealing

Top-gate zinc oxide thin-film transistors have been fabricated by thermal atomic layer deposition, and the effective process steps to improve the device stability have been investigated in detail. In particular, the incorporation of triple rapid thermal annealing steps in oxygen ambient has been proposed to shift the turn-ON voltage toward the positive direction, reduce interface defects, and suppress gate leakage current. Such devices exhibited near zero turn-ON voltage and significantly enhanced electrical and environmental stability. Repeated I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</sub> -V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GB</sub> sweeping over 900 times in air ambient only caused a shift of the transfer characteristics as low as 0.08 V. Both positive and negative gate bias stress tests on such devices exhibited superior stability performance. Furthermore, ring oscillators based on these devices were found to be capable of highly stable continuous operation over 10 000 s, indicating the devices' suitability for practical circuits-on-glass applications.

High performance self-aligned top-gate ZnO thin film transistors using sputtered Al2O3 gate dielectric

High performance self-aligned top-gate zinc oxide (ZnO) thin film transistors (TFTs) utilizing high-k Al2O3 thin film as gate dielectric are developed in this paper. Good quality Al2O3 thin film was deposited by reactive DC magnetron sputtering technique using aluminum target in a mixed argon and oxygen ambient at room temperature. The resulting transistor exhibits a field effect mobility of 27cm2/Vs, a threshold voltage of −0.5V, a subthreshold swing of 0.12V/decade and an on/off current ratio of 9×106. The proposed top-gate ZnO TFTs in this paper can act as driving devices in the next generation flat panel displays.

High-performance and room-temperature-processed nanofloating gate memory devices based on top-gate transparent thin-film transistors

Transparent nanofloating gate memory devices based on top-gate zinc oxide thin-film transistors were developed. The proposed devices contained a facile and dry-synthesized palladium nanocluster array as a charge-trapping layer. The good programmable memory characteristics were exhibited due to the thin tunneling oxide, caused by the top-gate structure. The good endurance, data retention capability, and environmental stability demonstrated by the proposed device made it suitable for nonvolatile memory applications. As the whole processes were carried at room temperature, this letter has a potential use in fabricating high-performance and high-reliability nonvolatile memory devices on flexible substrates.