Electrostatics and electrical transport in semiconductor nanowire Schottky diodes

Abstract

The electrostatics and electrical transport characteristics in semiconductor nanowire Schottky diodes are studied using three-dimensional finite-element simulations. From the simulations, the dependences of the depletion region width on the bias and the doping level are found to deviate significantly from the relations in the bulk Schottky model, indicating different electrostatic properties in nanowire Schottky junctions. Furthermore, simulations of the current-voltage relation, which is corroborated by experimental measurements, demonstrate that the standard analytical model is not sufficient to describe current-voltage characteristics in nanowire Schottky diodes. An important implication is that the commonly used analytical model is not valid for extracting the ideality factor and the Schottky barrier height. These findings suggest that numerical simulations are critical to evaluating nanoscale device performance and guiding device development efforts.