STUDY OF PROTON BINDING-SITES AT THE SILICON DIOXIDE-ELECTROLYTE INTERFACE WITH CONDUCTANCE SPECTROSCOPY

Abstract

The kinetics of trapping and detrapping of protons at surface sites on thermally grown SiO2 have been studied in detail. A Shockley-Read-Hall-type model has been used to model trapping and detrapping of protons at these sites which behave as traps with two levels. A small signal equivalent circuit is obtained. The model has been validated with extensive imittance measurements on electrolyte-oxide-semiconductor structures. From the conductance frequency measurements, the response time of these traps is of the order of a few milliseconds which would also be the intrinsic response time of ion sensitive field effect transistor. The approach is quite general and could be used for studying trapping-detrapping of ions or charged molecules at other electrolyte-insulator interfaces.