Silicon-On-Insulator Bulk Acoustic Wave Disk Resonators

This paper introduces the design and implementation of center-supported bulk acoustic wave (BAW) disk resonators on silicon-on-insulator (SOI) substrates. The use of a SOI substrate enables implementation of single crystal silicon disk resonators and provides electrical isolation between the disk and the substrate. A center-supported 800mum in diameter single crystal silicon disk resonator operated in a high order in-plane degenerate mode at 5.9MHz demonstrates an ultra high quality factor (Q) of 243,000. Lateral BAW disk resonators have the potential to be employed in filters, frequency references and sensors (in particular vibratory gyroscopes)