Device scaling in sub-$100nm$ pentacene field-effect transistors

Reported here is the fabrication of $20–100nm$ channel length pentacene field-effect transistors (FETs) with well-behaved current-voltage characteristics. Using a solution deposition method, pentacene grains span entire devices, providing superior contacts. Varying the gate oxide thickness, the effects of scaling on transistor performance is studied. When the channel length to oxide thickness exceeds 5:1, electrostatically well-scaled nanometer FETs are prepared. The results show that the device characteristics are dominated by the contacts. Decreasing the oxide thickness lowers the device turn-on voltage beyond simple field scaling, as sharper bending of the gate potential lines around the contacts more effectively reduces the molecule/source interfacial resistance.