Transport properties of gated resonant tunneling diodes in the single electron regime

To investigate the transport properties of resonant tunneling diodes with d imensions in the submicron range, small area mesa diodes with surrounding S chottky gates have been processed. The gate turns out to provide excellent current control, which makes a resonant tunneling transistor operation mode feasible for our devices. In the single electron regime very distinct stai rcase-like features are observed in the current voltage characteristics. An accurate analysis of this staircase characteristic by means of magnetotran sport measurements shows that tunneling through defect states can be ruled out as a reason for these current steps. Moreover, we show that the current steps are exclusively due to quantization effects of the gate potential. A t high magnetic fields a saturation-like behavior of the step onset voltage s occurs as a function of a magnetic field applied parallel to the directio n of transport. This effect can be explained by boundary conditions for the electron number and the Fermi level in the electron supply layer next to t he double barrier structure. (C) 1998 American Institute of Physics. [S0021 -8979(98)01224-9].