A PECVD diamond device for chemical gas sensing applications

This paper presents a new diamond based microelectronic gas sensor for appl ications that require operation at a higher and wider temperature range and in harsh environments such as process control, exhaust emission and engine monitoring. The CO gas sensing performance and detection mechanism of the new sensor have been studied by using I-V and I-t characteristics as a func tion of gas concentration over a wide temperature range (50-500 degrees C). The gas sensitivity of the sensor is high, repeatable and reproducible. Th e response time is in seconds to a small concentration of CO gas. Gas detec tion mechanism of the new sensor is attributed to the modification of the o xygen vacancies in the SnOx layer through the reduction reaction between pr e-adsorbed oxygen and CO gases. (C) 1998 Published by Elsevier Science S.A. All rights reserved.