Thermally compensated aluminum nitride Lamb wave resonators for high temperature applications

Abstract

In this letter, temperature compensation for aluminum nitride(AlN)Lamb wave resonators operating at high temperature is presented. By adding a compensating layer of silicon dioxide ( SiO 2 ) , the turnover temperature can be designed for high temperature operation by varying the normalized AlN film thickness ( h AlN / λ ) and the normalized SiO 2 film thickness ( h SiO 2 / λ ) . With different designs of h AlN / λ and h SiO 2 / λ , the Lamb wave resonators were well temperature-compensated at 214 ° C , 430 ° C , and 542 ° C , respectively. The experimental results demonstrate that the thermally compensated AlNLamb wave resonators are promising for frequency control and sensing applications at high temperature.