Regensburg 2007 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 11: Quantum dots and wires: Transport properties I
HL 11.2: Vortrag
Montag, 26. März 2007, 15:00–15:15, H15
Scaling analysis of transport properties of GaAs-based nanocolumns — •Jakob Wensorra1, Klaus Michael Indlekofer1, Mihail Ion Lepsa1, Katharina Peter1, Arno Förster2, and Hans Lüth1 — 1Centre of Nanoelectronic Systems for Information Technology (IBN-1), Research Center Jülich, 52425 Jülich, Germany — 2Aachen University of Applied Sciences, Section Jülich, D-52428 Jülich, Germany
Semiconductor nanocolumns are ideal systems not only for basic research in the field of quantum transport but also for finding novel nanodevice concepts for information technology. By means of built-in heterostructures, one can easily implement tunnel barriers and quantum well structures within such nanocolumns, with tailored electronic transport properties.
We present a scaling analysis of quantum transport properties of GaAs-based resonant tunnelling nanocolumns down to 30 nm lateral dimensions. The electronic transport properties of the smallest devices are strongly influenced by the lateral depletion region, which defines the vertical conductive channel within the device. Simulations of the 2D-potential map of the device structure suggest a transport model based on a quantum collimation effect due to a saddle point in the potential profile. For structures with a lateral dimension of 60 nm - 45nm, this quantum collimation effect leads to a distinct improvement of the nanodevice performance at room temperature. For the lowest dimensions (< 45 nm) we observe a degradation of device performance due to a depletion of the channel within the nanocolumns.