Dresden 2009 – scientific programme

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DS: Fachverband Dünne Schichten

DS 30: Application of Thin Films I

DS 30.4: Talk

Thursday, March 26, 2009, 15:00–15:15, GER 37

Effect of the interface roughness on the performance of nanoparticulate zinc oxide field-effect transistors — •Koshi Okamura, Norman Mechau, Donna Nikolova, and Horst Hahn — Forschungszentrum Karlsruhe, Institute of Nanotechnology, Karlsruhe, Germany

Field-effect transistors (FETs) based on nanocrystalline inorganic materials have been attracting interests as a candidate for printable electronics. Nanocrystalline FETs take the advantage of compatibility with low-temperature and high throughput processes. However, the critical parameter of nanocrystalline FETs is the interface roughness between the nanocrystalline semiconductor and the insulator, where the channel of the FET is formed. Therefore, the correlation between the interface roughness and the performance of nanoparticulate ZnO FETs is systematically investigated. ZnO nanoparticles were dispersed in 2-methoxyethanol with stabilizer at a fixed concentration and processed by ultrasonic treatments. The agglomerate sizes were changed by the duration time, so that the resulting films had different degree of roughness at the interface. The FETs in the bottom-gate configuration were fabricated from suspensions, consisting of a Si substrate, a SiO₂ layer, a spin-coated nanoparticulate ZnO layer and Al source and drain electrodes. The FET with the lowest average roughness of 47.4 nm showed the best mobility of 8.4·10^-3cm²/Vs. In contrast, the FET with the highest roughness of 70.6 nm showed two orders of magnitude lower mobility of 8.7·10^-5cm²/Vs. These results indicate the strong correlation between the interface roughness and the FET performance.