Investigations on quality factor of high frequency laterally vibrating LN on SiO2 microresonators

This paper presents an investigation on the quality factor (Q) of Laterally Vibrating Resonators (LVRs) based on thin films of Y-cut ion-sliced Lithium Niobate (LN) on silicon dioxide (SiO₂) that were first demonstrated in [1]. Devices operating between 500 MHz and 1.5 GHz were designed and fabricated to explore the dependence of Q on: (i) electrode coverage and location, (ii) air damping, (iii) temperature, (iv) frequency, and (v) vibration mode. A considerable increase in Q was attained when using smaller electrode coverage or strategically placing the electrodes at low strain locations. These results clearly indicate the impact of interfacial loss on Q. A minimal dependence of Q on pressure was found, implying that air damping has a minor effect in setting Q for these devices. Q vs. temperature of a characteristic resonator was also measured, hinting that damping mechanisms of thermoelastic nature are dominant in these devices.