An Integrated Sensor for Electrochemical Measurements

Abstract
A method for the fabrication of a completely integrated solid-state electrochemical sensor which combines a minature liquid junction reference electrode with a CMOS ISFET is presented. The reference electrode is fabricated by preferentially etching silicon to form a porous silicon frit. The CMOS process provides electrical encapsulation of the ISFET. The performance of the reference electrode and CMOS ISFET as an integrated sensor is demonstrated.