HIGH TRANSCONDUCTANCE IN-PLANE-GATED TRANSISTORS

Focused-ion-beam written one-dimensional field-effect transistors are fabricated and characterized at room temperature. By writing these in-plane-gated channels with geometrical widths of 0.2-1.1-mu-m in heterostructures, we obtain one-dimensional transconductances of up to 170-mu-S for two channels in parallel. We determine the effective width of the channels, which ranges between 790 nm and zero, being still reproducibly tunable at a few nanometers. The reproducibility in fabrication already of the prototypes presented here is sufficient for integration applications. We observe current densities, which can only be explained by a strong velocity overshoot of the electrons and promises excellent high-frequency behavior of the device. The in-plane-gate transistor does not need any alignment and can easily be interconnected and integrated with a writing speed exceeding 10(6) devices per s.