Parameter Uniformity of Submicron-Channel-Length Organic Thin-Film Transistors Fabricated by Stencil Lithography

Using high-resolution stencil lithography, we have fabricated bottom-gate, top-contact (inverted staggered) organic thin-film transistors that have a channel length of 0.5 μm and gate-to-source and gate-to-drain overlaps of 2 μm. Owing to the small channel length, the transistors have a large width-normalized transconductance of (0.50 ± 0.05) S/m, despite the relatively small charge-carrier mobility of (0.36 ± 0.04) cm
²
/V · s. Across an array of 16 transistors, the uniformity of the transconductance is about 9% (1σ), the uniformity of the carrier mobility is about 7%, the uniformity of the threshold voltage is about 4%, the subthreshold slope varies between 95 and 150 mV/decade, and the on/off current ratio varies between 7 × 10
⁴
and 3 × 10
⁶
. To our knowledge, this is the first time that the parameter distribution of submicron-channel-length organic TFTs is reported.