RESONANT BEHAVIOR OF THE SI/FLUORIDE INTERFACE - A METHOD FOR TESTING THE UNIFORM ACCESSIBILITY OF AN ELECTRODE SYSTEM

The p-Si/fluoride interface exhibits a resonant behavior in the anodic potential region. The resonance frequency is proportional to the interface current density. It is shown that the response of the interface to a potential step excitation provides a direct means for accessing the current distribution at the interface. When the current density is under mixed (mass transport + kinetic) control, this gives a simple test for the uniform accessibility of the electrode. This method is tested on a circulation cell, where the current distribution can be varied by changing the geometry. The obtained current distributions are qualitatively consistent with a numerical calculation of the current-density map.