Integration of a sensitive material to a silicon-based device for CO detection

Abstract A sensitive semiconductor oxide has been successfully integrated to a silicon-based prototype of sensor for environment pollution as CO. The sensitive material SnO 2 includes catalyst Pd aggregates and provides a low temperature detection (80–120°C) by conductance change (sensitivity S =( G − G 0 )/ G 0 =60 at 120°C for 50 ppm CO in air in steady state and S =8 in dynamic regime). The 〈100〉 silicon substrate, coated by a Si 3 N 4 insulating film, includes a micro-heater, a temperature measuring resistor, and Pt interdigital electrodes, covered with the sensitive material integrated using a Ultrasonic Submicronic Aerosol Pyrolysis process at atmospheric pressure. The operating cycle of the system has been studied, regarding to the necessity to reactivate the sensitive material at regular intervals by heating at higher temperature.