单晶LNBAW谐振器有限元仿真研究

利用离子注入剥离法(CIS)制备的铌酸锂(LN)压电薄膜可用于制备体声波(BAW)器件,近年来备受关注。滤波器的指标与谐振器的性能密切相关,但基于LN单晶薄膜的BAW谐振器,对其结构的仿真优化还未有较深入的报道。该文以LN单晶薄膜为核心压电层材料,构建了固态反射型(SMR)单晶薄膜谐振器有限元仿真模型,对其压电层厚度和布喇格反射层厚度进行了设计,并重点针对谐振器上电极的台阶结构进行了二维模型仿真,为高频LN BAW滤波器的制备提供了理论依据。

FEM Simulation Study on Single Crystalline LN BAW Resonator

The single crystalline lithium niobite(LN) piezoelectric thin film fabricated by crystal-ion-slicing(CIS) technique can be used as the piezoelectric layer in bulk acoustic wave (BAW) devices, which has attracted increasing attention in recent years. The performance of BAW filter is closely related to that of BAW resonator, but the simulation and optimization of the BAW resonator based on LN single crystalline film has not been reported in depth. In the present work, the FEM simulation model of the solid-mounted resonator (SMR) is established by using the single crystalline LN thin film as the core piezoelectric layer material, the thickness of the piezoelectric layer and the Bragg reflector layer are designed, with an emphasis on the two-dimensional model simulation of the step structure of the top electrode of the resonator, which provides a theoretical basis for the preparation of high frequency LN BAW filter.