SUBMICRON VERTICAL ALGAAS GAAS RESONANT-TUNNELING SINGLE-ELECTRON TRANSISTOR/

We explore vertical transport phenomena. in sub-micron asymmetric AlGa As/GaAs double barrier structures (DBS's) by applying a bias to a spec ial Schottky side gate which allows the effective area of the conducti ng channel to be adjusted or ''tuned''. The AlGaAs barriers are select ively doped to generate Excess electrons in the GaAs well, and thus si ngle electron transistor (SET) operation is possible because the numbe r of electrons in the quantum dot can be varied one-by-one with the si de gate. Gate modulation of the drain current flawing through the cond ucting channel is found to be strong, and this allows us to study Coul omb blockade, electron-electron interactions and lateral confinement e ffects. Observation of a broad (approximate to 18 mV) current plateau at low bias when the quantum dot is occupied by a single electron, sug gests that this technology is very promising for the realization of SE T operation at temperatures well above 4.2 K.