Unipolar accumulation-type transistor configuration implemented using Si nanowires

A unipolar accumulation-type field effect transistor (FET) is proposed, fabricated, and characterized. The device, which uses a single doping type and Ohmic contacts, relies on the nanoscale to force the only possible source-drain path to pass through an accumulated (on state) or depleted (off state) region. The transistor is demonstrated using silicon nanowires (SiNWs) grown on glass with our nanochannel-template-guided "grow-in-place" approach. The resulting SiNW FETs exhibit an on-off ratio of 106 and a subthreshold slope of 130 mV /decade. These transistors can allow unique design flexibility; for example, a NAND gate can be achieved in a uniformly doped nanowire with four contacts.