The stability of Pt heater and temperature sensing elements for silicon integrated tin oxide gas sensors

Good performance of alarm systems and environmental as well as industrial control methods requires an optimal operation of the gas sensors involved. An essential point related to this challenge is an accurate control of the sensor working temperature. Therefore, the stability of the Ti/Pt heater element used in tin oxide thin film gas sensors has been investigated. It turns out that the heater element is influenced by diffusion and oxidation processes taking place during thermal treatment. This is illustrated by RBS, AES and XPS measurements. The modifications in chemical composition are also found to influence the electrical characteristics R0 and TCR of the heater.