Observation of transport in mesoscopic honeycomb-shaped networks

An electronic transport was observed in honeycomb-shaped mesoscopic (submicron) networks at liquid helium temperature. These networks were manufactured 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 switching on the I-V characteristics was explained in the framework of the model of a dynamic random resistor network. The existence of the patterned part of the thick, moderately doped, n-GaAs epilayer was the reason for the increase of the compensation ratio, the ionization energy and, as a result, the threshold voltage of the impact ionization of the shallow donor impurity level in the bulk of the epilayer.