Microelectroplating Silver on Sharp Edges toward the Fabrication of Solid-State Nanopores

Abstract

Electrodeposition of silver was investigated as a fabrication tool for constricting large vias in silicon substrates while leaving a small opening in the center of the via. Silver reduction from ammoniacal silver nitrate was studied at electrodes of novel geometry, i.e., the edge of the vias, with respect to reduction potential, reduction pulse type, and pulse duration. A variety of crystal nucleation and growth patterns were observed and characterized by scanning electron microscopy. It was found that electroplated silver occluded the vias to leave open areas of less than 1 μm2. Such occlusions might be used as restrictions in microfluidics systems, forming a type of solid-state micropore or nanopore. © 2004 The Electrochemical Society. All rights reserved.