Electrode Phenomena during Anodic Bonding of Silicon to Sodium Borosilicate Glass

Abstract

Electrode phenomena during anodic bonding of silicon to sodium borosilicate glass are examined. The cathodic reaction, reduction of sodium, does not usually limit the reaction rate. The anodic reaction, oxidation of the silicon, requires very high electric fields in the anodic depletion layer and is the limiting electrode reaction. The ohmic drop in the glass determines the rate of establishment of the high interfacial fields. The transient current response under constant voltage conditions is modeled over the timescale of interest for bonding by a simple equivalent circuit. The current response model is also applicable to the initial transient during electrode polarization of glass at a blocking anode.