Application of Micromachined Y -Cut-Quartz Bulk Acoustic Wave Resonator for Infrared Sensing

• Published in: Journal of microelectromechanical systems Vol. 20; no. 1; pp. 288 - 296
• Main Authors: Pisani, M B, Kailiang Ren, Ping Kao, Tadigadapa, Srinivas
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.02.2011; Institute of Electrical and Electronics Engineers
• Subjects: Acoustics; Applied sciences; Bulk acoustic wave resonator; Detection; Detectors; Electronics; Exact sciences and technology; heterogeneous microelectromechanical systems integration; Imaging; Impedance; infrared (IR) detector; Infrared radiation; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Microelectronic fabrication (materials and surfaces technology); Micromachining; Micromechanical devices and systems; Micromechanics; Noise; Noise equivalent temperature difference; Optical resonators; Physics; Precision engineering, watch making; quartz micromachining; Resonant frequency; Resonators; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Temperature measurement; Temperature sensors; thermal IR sensor; Y -cut quartz; Infrared thermography; Bulk acoustic wave resonator; Tracking; Micromachining; Bulk wave; Y-cut quartz; Frequency measurement; Quartz; infrared (IR) detector; Quartz resonator; quartz micromachining; Resonance frequency; thermal IR sensor; Silicon; Thermal imaging; High frequency; Microelectromechanical device; Pixel; Room temperature; heterogeneous microelectromechanical systems integration; Production process
• ISSN: 1057-7157; 1941-0158
• DOI: 10.1109/JMEMS.2010.2100030

This paper presents the design, fabrication, and characterization of thermal infrared (IR) imaging arrays operating at room temperature which are based on Y-cut-quartz bulk acoustic wave resonators. A novel method of tracking the resonance frequency based upon the measurement of impedance is presented. High-frequency (240-MHz) micromachined resonators from Y-cut-quartz crystal cuts were fabricated using heterogeneous integration techniques on a silicon wafer. A temperature sensitivity of 22.16 kHz/°C was experimentally measured. IR measurements on the resonator pixel resulted in a noise equivalent power of 3.90 nW/Hz 1/2 , a detectivity D* of 1 × 10 5 cm · Hz 1/2 /W, and a noise equivalent temperature difference of 4 mK in the 8- to 14-μm wavelength range. The thermal frequency response of the resonator was determined to be faster than 33 Hz, demonstrating its applicability in video-rate uncooled IR imaging. This work represents the first comprehensive thermal characterization of micromachined F-cut-quartz resonators and their IR sensing response.