The Ideal Nanowire Transistor-Materials Development for Contact-Doped ZnO Nanowires
Final Report Abstract
We have demonstrated high-performance top-gate field-effect transistors based on ZnO nanowires and a hybrid organic/inorganic gate dielectric consisting of a self-assembled monolayer and aluminum oxide. The hybrid dielectric forms naturally when aluminum is thermally evaporated onto a SAM-covered ZnO nanowire, since atmospheric oxygen can penetrate the interface between SAM and aluminum. Cross-sectional TEM images indicate that the aluminum gate electrode is only poorly wetting the SAM-covered ZnO nanowire, which is beneficial for the penetration of atmospheric oxygen. The transistors have an on/off current ratio of 109, a subthreshold slope of 100 mV/dec, and a transconductance of 50 µS. The hybrid gate dielectric allows operating the transistors at voltages up to 3 V, making them fully compatible with organic LEDs. Inverters based on ZnO nanowire transistors with hybrid gate dielectric operate at frequencies up to 30 MHz. As the maximum temperature during the fabrication of the hybrid gate dielectric is 100 °C, the developed process is compatible with flexible polymeric substrates.
Publications
- “Top-Gate ZnO Nanowire Transistors and Integrated Circuits with Ultrathin Self-Assembled Monolayer Gate Dielectric,” Nano Letters, vol. 11, pp. 5309-5315, 2011
D. Kälblein, R. T. Weitz, H. J. Böttcher, F. Ante, U. Zschieschang, K. Kern, H. Klauk
- “High-Performance ZnO Nanowire Transistors with Aluminum Top-Gate Electrodes and Naturally Formed Hybrid Self-Assembled Monolayer/AlOx Gate Dielectric,” ACS Nano, vol. 8, pp. 6840-6848, 2014
D. Kälblein, H. Ryu, F. Ante, B. Fenk, K. Hahn, K. Kern, H. Klauk
(See online at https://doi.org/10.1021/nn501484e)
