Keywords: Resonators, MEMS, sensors, harsh environment, oscillator
Summary:The heart of-high precision sensors and oscillators serving current needs are piezoelectric resonators, particularly made of quartz, known for high sensitivity, accuracy, and stability. However, quartz is limited to less than 250 °C. Silicon MEMS based sensors and oscillators are also restricted well below 250 °C while Silicon Carbide and Aluminum Nitride based sensors and oscillators capable of operating in the above 250 °C range do not provide the high sensitivity, accuracy, and stability of single crystal quartz. High precision applications requiring such sensors and oscillators are quite diverse, and include interplanetary spacecraft, Generation 4 nuclear reactors, deep drilling, enhanced geothermal systems, hypersonic aircrafts and missiles, to name a few. A technology with the promise to extend the functionality of quartz resonators using high temperature piezoelectric materials will be presented. Wafer level fabrication and packaging techniques will have the potential of providing ruggedness, small foot-print, and lower cost.