The thin film bulk acoustic wave resonator based on single-crystalline 43○Y-cut lithium niobate thin films
Xiaoyuan Bai, Yao Shuai, Lu Lv, Ying Xing, Jiaoling Zhao, Wenbo Luo, Chuangui Wu, Tao Yang, Wanli Zhang
Abstract
43°Y-cut lithium niobate (LiNbO3, LN) single-crystalline thin films, which are integrated with two types of Bragg reflectors of W/SiO2 and Mo/SiO2, respectively, are fabricated by means of the crystal-ion-slicing technique. Crack-free LN thin films are obtained when the Mo/SiO2 reflector is adopted, while crumples take place when the LN thin film is combined with W/SiO2. Moreover, solidly-mounted-type thin film bulk acoustic wave resonators (LN-SMRs) based on the single-crystalline LN film and Bragg reflector layers of Mo/SiO2 are prepared and characterized. The results indicate that the LN thin film combined with the Mo/SiO2 reflector has good thin film quality, and keff2 of the LN-SMR reaches 20%.