Observation of transport in mesoscopic honeycomb-shaped networks

An electronic transport was observed in honeycomb-shaped mesoscopic (submic ron) networks at liquid helium temperature. These networks were manufacture d by the reactive ion etching of highly (nearly degenerated) and moderately doped n-GaAs epilayers through the initially structured, by self-organised patterning, polymer masks. The free electron transport was observed in the networks of thin, highly doped, n-GaAs epilayer. The detected multiple swi tching on the I-V characteristics was explained in the framework of the mod el of a dynamic random resistor network. The existence of the patterned par t of the thick, moderately doped, n-GaAs epilayer was the reason for the in crease of the compensation ratio, the ionization energy and, as a result, t he threshold voltage of the impact ionization of the shallow donor impurity level in the bulk of the epilayer. (C) 1999 Academic Press.