Nanoscale Device Isolation Of Organic Transistors Via Electron-Beam Lithography

We investigated the use of electron-beam lithography on pentacene and poly(3-hexylthiophene) field-effect transistors to achieve device isolation and enable the realization of nanoscale organic circuits. We determined the doses and exposure linewidths needed to suppress carrier transport, enabling direct patterning at the nanoscale. The precision limits were also studied through an analysis of proximity scattering effects. With an optimized pattern and exposure, we reduced off-currents by almost four orders of magnitude and gate leakage by three orders of magnitude on backgated devices. Our electron-beam isolation methods also increased the on/off ratio and drastically improved the subthreshold swing, thus attesting to the viability of this technique for patterning of organic circuits at the nanoscale. (C) 2005 American Institute of Physics.