光学精密工程2009，Vol.17Issue(6)：1251-1256,6.
独特谐振模式下薄膜体声波谐振器的设计
Design of thin film bulk acoustic resonatorunder unique mode
摘要
Abstract
The spectra of input electric impedance for a four-layer (electrode/piezoelectric film/electrode/substrate) thin Film Bulk Acoustic Resonator (FBAR) with the materials of Al/AlN/Al/Si and the thickness of each layer of 0.8 μm/1.9 μm/0.8 μm/100 μm is researched by a transfer matrix method. The distribution of the effective coupling factor (k2eff) versus the mode order is derived,and a unique mode with maximumk2eff is obtained in the 40th mode from 1 GHz to 2 GHz in simulation. The effects of various electrodes and the substrates on the distribution of unique mode and the frequency shift are studied,and the quality factor at series resonant frequency and the Figure of Merit (FOM) which are the main parameters to indicate the features of the crystal resonator in a filter design are investigated.Experimental results show that the performance of the FBAR working in the unique mode relies greatly on the sizes and the materials of layers. The unique mode shifts in a higher frequency are from 1.2 GHz to 4.8 GHz when the film thicknesses come from 0.2 μm to 4.3 μm in simulation;thek2eff and Qs are from 3.2% to 0.8% and from 2 000 to 700 in simulation,respectively when the substrate becomes thicker and thek2eff of the unique mode declines and tends to a stable value when the electrode becomes thicker.These conclusion gives some guidelines for the design of a proper FBAR.关键词
薄膜体声波谐振器/有效机电耦合系数/品质因数Key words
Film Bulk Acoustic Resonator(FBAR)/effective electromechanical coupling factor/quality factor分类
信息技术与安全科学引用本文复制引用
莫绍孟,陈剑鸣,吴光敏,赵建军..独特谐振模式下薄膜体声波谐振器的设计[J].光学精密工程,2009,17(6):1251-1256,6.基金项目
Supported by Key MEMS Project Construction of KMUST( Grant No. 14078024) （ Grant No. 14078024）
