Micromachined resonant temperature sensors: theoretical and experimental results

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control Vol. 47; no. 2; pp. 333 - 340
• Main Authors: Leblois, T.G., Tellier, C.R.
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.03.2000; The Institute of Electrical and Electronics Engineers, Inc. (IEEE); Institute of Electrical and Electronics Engineers
• Subjects: Electrical resistance measurement; Engineering Sciences; Equations; Ferroelectric materials; Frequency; Micro and nanotechnologies; Microcavities; Microelectronics; Micromachining; Micromechanics; Motional; Piezoelectricity; Q factors; Resonance; Resonators; Temperature distribution; Temperature sensors; Tensile stress; Wet etching
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/58.827417

Describes the study of quartz temperature sensors based on new bulk acoustic wave microresonators operating in thickness modes. First, we compare the thermal sensitivity and the electromechanical coupling coefficients of singly or doubly rotated cuts. These investigations allow us to select some cuts with both a good thermal sensitivity and piezoelectric characteristics. In the second part, emphasis is placed on the micromachining of resonators suspended by four bridges. These two theoretical considerations lead to the choice of three cuts. Experimental measurements are then presented. The temperature-frequency characteristics of the resonators are measured over the range 20 to 100 /spl deg/C. Motional resistances and Q factors are determined at room temperature.