Electrical Characterization of Multisensor Elements with Ferroelectric Nanocoatings

Abstract

This paper presents the fabrication technology and main sensing characteristics of multisensor elements responding to force and temperature variation simultaneously. The sensors are based on silicon membranes of different sizes and patterns, coated with a LiTaO3 ferroelectric thin film. It was found out that the meander patterned membrane with a size of $65\ \mu\mathrm{m}$ exhibited the most favorable piezoelectric and pyroelectric behavior, producing a piezoelectric coefficient of 9 pC/N with a linearity error of 0.14 % and sensitivity of 0.41 pC/N. It is also characterized by a pyroelectric voltage of 228 mV for the dynamic range up to 48 C°. The proposed element could be easily integrated with the conventional microfabrication technology, by applying a low number of photomasks, making it simple and low-cost. In addition, there is a negligible variation of the sensor arrayparameters across the wafer. Possible application of the device could be fluids level and temperature measurements for different industrial needs.