Piezoelectrically Activated Silicon Resonators

This paper describes the feasibility and performances of two families of AIN/Si resonators: 1 MHz extensional and 20 to 100 kHz flexural resonators. In both components the resonating structure is obtained with SOI silicon suspended beams driven by an AIN piezoelectric layer. The 1MHz resonator exhibits a Q factor larger than 100 000 under vacuum and a coupling coefficient of 0.06%. The 20 to 100kHz resonators exhibit extremely low thermal drift of resonant frequency (alpha close to zero). The thermal compensation has been obtained at device-level by using SiO₂ with an appropriate thickness.