Materials and processing for realization of micro-hotplates operated at elevated temperature

Micro-pellistors and conductivity-type gas sensors are among the most promising candidates for the monolith integration of gas-sensing elements in olfactory gas detection. Both types have to be operated at elevated temperatures of 200-600°C; therefore, the formation of thermally isolated integral micro-hotplates is the key element in the development of the array. In this paper, the alternative processes are discussed with emphasis on thermal isolation, selection of the appropriate structural materials, formation of stable contacts to the filaments and deposition of gas-sensitive layers. The results of thermal and mechanical model calculations were confirmed by experimental measurements.