Mo/Ti multilayer Bragg reflector for LiNbO3 film bulk acoustic wave resonators

A 43 degrees rotated Y-cut LiNbO3 (LN) single-crystal thin film coated with a bottom electrode and a Mo/Ti Bragg reflector is successfully transferred onto the 4-in. LN wafer substrate by means of crystal-ion-slicing (CIS) technique and benzocyclobutene bonding method. The multilayer film is crack-free, and the Mo/Ti reflector shows good acoustic reflection efficiency. A thin film bulk acoustic wave resonator based on the Mo/Ti Bragg reflector and the LN thin film (LN-BAW) is prepared, and the properties are further analyzed. The results indicate that the LN-BAW provides a large K-t(2) of similar to 16.63% and the Q-factor and figure-of-merit of the LN-BAW reach 183 and 30.4, respectively.