Non-silicon MEMS platforms for gas sensors

The target of this work is the demonstration of advanced approaches able to provide non-silicon MEMS platforms for chemical sensor operating under harsh environmental conditions and, on the other hand, to assure microhotplate stable at high temperature, which can be used for the deposition of refractory gas-sensing materials, for example, oxides of gallium, zirconium, or hafnium. Non-silicon materials that can be used for these MEMS platforms include aluminum oxide, yttria-stabilized zirconia and thin borosilicate glass. It was shown that thin ceramic films made of oxide materials can withstand annealing temperature up to 1000 °C, MEMS sensor based on these films consumes <70 mW at continuous heating at 450 °C and ∼1 mW in pulsed heating operation mode. Ceramic MEMS show higher stability at high temperature compared to silicon technology based MEMS, whereas power consumption of both types of devices is comparable.