Characterization of a single port aluminum nitride tuning fork

In this study the characterization of an aluminum nitride (A1N) double ended tuning fork (DETF) fabricated on a layer of silicon dioxide (SiO₂) is presented. The positive temperature coefficients of SiO₂ are used to achieve zero TCF for radio frequency (RF) Lamb wave resonators. This paper shows the possibility to integrate temperature compensated Lamb wave resonators with DETF-based devices on a single chip. The DETF resonates in a quasi-in-plane mode shape with a Q-factor of 578 in air and 3028 in vacuum. Through a laser Doppler velocity (LDV) measurement we also show that, due to the biomorph nature of the structure and the angle of the side walls, the motion of each tine of the DETF is a combination of in-plane bending, out-of-plane bending and torsional motion around the beam main axis.