Resonant tunneling in submicron double-barrier heterostructures

We have fabricated submicron resonant tunneling devices from double-barrier AlGaAs/GaAs heterostructures using electron beam lithography and wet chemical etching. These devices exhibit step-like features in the current-voltage curves. We interpret these steps as arising from additional size quantization of the electronic states in the well due to in-plane lithographic confinement. Magnetotunneling experiments on these devices are reported for the first time. A simple model calculation describes well the experimental data.