Conference Program - LOPE-C 2011

SCIENTIFIC CONF. | WEDNESDAY-JUNE 29, 2011
Track 4
Organic Transistors (02:30 pm - 04:00 pm) | LOCATION HARMONIE D / LEVEL C2
03:00 pm Submicron organic thin film transistors fabricated by UV nanoimprint and self-aligned photolithography
Dr Herbert Gold,
JOANNEUM RESEARCH ForschungsGesmbH, Austria
The miniaturization of organic thin film devices is a key issue for enhancement of integration level and switching speed for future applications in large area printed organic
circuits. In this study we report on a novel fabrication method for organic thin film transistors with channel lengths of several microns and down to the submicron regime.
In a first step the aluminum gate electrodes were structured by residue free UV nanoimprint lithography [1]. For the dielectric layer a UV-cross linkable gate dielectric
structured by photolithography, was used. The gold source and drain electrodes were structured by self aligned photolithography [2] performed by backside exposure
through the micron and submicron gate electrodes. Finally, thermally evaporated pentacene was used as organic semiconducting layer. The contact resistance and the
pentacene growth were optimized by a UV-ozone pretreatment of the gold electrode and the dielectric layer [3].
The overlap of the gate and source/drain electrodes can be minimized by optimizing the exposure time for the backside exposure as demonstrated by Transmission
Electron Microscopy. The devices show an excellent behavior in terms of leakage currents and hysteresis effects. Fully functional small channel OTFTs based on n- and
p-type organic semiconductors were fabricated on glass as well as on flexible substrates. The low parasitic capacitance of the devices enables new applications of organic
devices with transition frequencies up to 400 kHz.
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