Optimization of passivation layers for corrosion protection of silicon-based microelectrode arrays

The protectivity of passivation layers decides on the lifetime of silicon-b ased sensor chips in liquid and corrosive media. In this study the barrier effect of different organic (spin-coated) and inorganic (PECVD) thin films in brine was investigated using a microelectrode array as a microsensor mod el. The corrosion resistance of the microelectrode array was optimized by u sing buried conducting tracks and duplex (SiO2/Si3N4) or tripler (SiO2/Si3N 4/SiO2) layers instead of inorganic monolayers. The failure mechanisms were investigated with respect to physical and mechanical effects, and corrosiv e attack. (C) 2000 Elsevier Science S.A. AU rights reserved.