Thermal transient characteristics of zinc oxide solidly mounted resonators

Thin film bulk acoustic wave (BAW) resonators have been the subject of research for many years due to their uses in wireless communications and chemical sensing. Both the steady-state and dynamic temperature characteristics of quartz resonators, such as those used in biosensing, have been studied in the past. Information pertaining to the steady-state temperature characteristics of ZnO BAW resonators is available in the literature, but thermal transient characteristics do not appear to be the subject of as much investigation. In this paper, we demonstrate the existence of transient thermal effects in ZnO solidly-mounted resonators (SMR). Resonators are exposed to a gradual and rapid temperature increase and the changes in five resonator parameters are compared. All five parameters are shown to vary linearly with temperature when exposed to a gradual temperature increase and vary in a parabolic manner when exposed to a rapid temperature increase, indicating the existence of thermal transient effects in these devices.