We present a versatile method to fabricate conical nanopores of different materials and shapes on silicon/silicon nitride chips for various nanoscale applications. We drilled silicon nitride membranes coated with photoresist with Focused Ion Beam (FIB) calibrated to the desired shape, followed by atomic layer deposition of a dielectric oxide and subsequent photoresist removal and annealing. We obtained conical nanopores made of SiO2 and Al2O3 on a silicon nitride membrane. We characterized the samples electrically, with Scanning Electron Microscopy (SEM), cross sections and Energy-Dispersive X-ray spectroscopy (EDX). We studied concave, straight, and convex nanopore shapes and measured their ionic current rectification effects, which vary with the nanopore geometry. We supported our experimental findings with numerical simulations based on the Poisson-Nernst-Planck model. With the addition of a metallic layer, we conducted enhanced Raman spectroscopy experiments to confirm the capacity of our structures to perform as tailored plasmonic antennas. Our results confirm the robustness and tunability of this fabrication method to produce conical nanopores of dielectric oxides for a wide range of applications and the potential of controlling the nanopore geometry.
The ICR (ionic current rectification) phenomenon in nanopores is influenced by both the shape and material of the nanopore, as well as the ion concentration within the electrolyte that permeates the nanopore. Specifically, nanopores composed of multiple materials can induce ICR due to variations in ion distribution along the nanopore-electrolyte interface across different sections of the material. In this study, we investigate the impact of configurations involving up to two layers of different materials (Si3N4 and Au) and six different electrolytes on solid-state nanoporous ICR. We aim to assess how different configurations of surface charges can influence ICR. The main advantage of nanopores made from gold and other metals may be their use as an ICR amplifier when illuminating nanopores with a wavelength of light lying in the plasmon resonance region of the metal used.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.