Non-Linear Gate Length Dependence of On-Current in Si-Nanowire FETs

An extensive gate-length (L_G) dependent electrical characterization of silicon nanowire (NW) field effect transistors (FET) is presented here. Catalytically-grown and nominally undoped Si-NWs were integrated as the active region of FETs, upon which fully silicided Schottky source and drain contacts were fabricated. The length of the active region was shortened by a desired value, through the lateral self-aligned formation of nickel silicide source- and drain-segments. All Si-NW FETs consisting of a single Si-NW with diameters between 10 and 30 nm display p-type behaviour and on/off-current ratios of up to 10 ⁷. Devices with L_Gs below 1 mum and 21 nm NW-diameters all show the same on currents around 1 muA at 1 V drain-source biases. For L_G > 1 mum the on-current decreases exponentially with increasing L_G