SiC based field effect gas sensors for industrial applications

The development and field-testing of high-temperature sensors based on sili con carbide devices have shown promising results in several application are as. Silicon carbide based field-effect sensors can be operated over a large temperature range, 100-600 degreesC, and since silicon carbide is a chemic ally very inert material these sensors can be used in environments like exh aust gases and flue gases from boilers. The sensors respond to reducing gas es like hydrogen, hydrocarbons and carbon monoxide. The use of different te mperatures, different catalytic metals and different structures of the gate metal gives selectivity to different gases and arrays of sensors can be us ed to identify and monitor several components in gas mixtures. MOSFET senso rs based on SIC combine the advantage of simple circuitry with a thicker in sulator, which increases the long term stability of the devices. In this pa per we describe silicon carbide MOSFET sensors and their performance and gi ve: examples of industrial applications such as monitoring of car exhausts and flue gases. Chemometric methods have been used for the evaluation of th e data.