Electrical characterization of truncated-pyramidal silicon nanopores in electrolyte solution

In this paper, electrical characteristics of truncated-pyramidal silicon nanopores under various electrolyte concentrations is investigated. The current-voltage (I-V) characteristic of the silicon nanopore differs from that of other asymmetric nanopore, due to the silicon/electrolyte interface property and the pyramidal pore shape. Low frequency 1/f noise in the testing system is measured. In diluted electrolyte solutions, non-ohmic behaviors are found in the I-V curves, and the nonlinearity increases with the decreasing of the electrolyte concentration. I-V characteristics of small nanopores are more nonlinear than the large ones, due to the enhanced influence of the electrical double layer (EDL) in small nanopores immersed in the electrolyte solution. Furthermore, the ionic current rectification (ICR) property in the nanopore with its pore mouth modified by SEM-induced deposition of hydrocarbon compounds is found. The shape modification induced by the hydrocarbons is modeled and analyzed.