Effect of electrolyte exposure on silicon dioxide in electrolyte-oxide-semiconductor structures

Abstract

The effect of hydration and ion penetration in silicon dioxide has been studied by fabricating metal-oxide-semiconductor capacitors on oxide exposed to acidic solutions with and without bias. Changes in oxide properties due to exposure have been probed using avalanche injection. Oxide charge build-up and interface state generation in the capacitors have been monitored. The measurements show that before avalanche injection the capacitance-voltage plots for the various electrolyte exposure conditions are similar. However, oxide integrity degradation is different for cathodic bias compared with anodic bias or no bias. This is due to penetration of protons or hydroxyl ions in the oxide, producing hydrogen-related defects that effect trapping and interface state generation.