Study of the CO Response of SiC Based Field Effect Gas Sensors

Abstract

The response characteristics of SiC based field effect gas sensors towards varying CO and O/sub 2/ concentrations over a wide temperature range and at atmospheric pressure has been studied in detail. Both thin, discontinuous as well as dense, homogeneous Pt films as the catalytic gate material in field effect transistor devices have been investigated and the results compared to CO oxidation characteristics over Pt/SiO/sub 2/ catalysts as reported in literature. Based on the results a hypothesis regarding the mechanism behind CO sensitivity of field effect devices is put forward, also emphasizing the importance of increased sensitivity to background hydrogen.