横向电场激励的剪切波AlN薄膜体声波谐振器  

AlN Thin Film Resonator Operated in Thickness Shear Mode Excited by Lateral Electric Field

作　　者：陈达[1] 李德华[1] 宋宏伟[1] 王翠玲[1] 张玉萍[1] 

机构地区：[1]山东科技大学理学院应用物理系,山东青岛266510

出　　处：《上海交通大学学报》2011年第3期327-330,335,共5页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金资助项目(61071016);山东科技大学"春蕾"计划项目(2009AZ056)

摘　　要：为了检测液体中的微量物质,研究了横向电场激励的剪切波固体装配型AlN薄膜体声波谐振器.器件以c轴择优取向的AlN薄膜作为压电层,电场由平行于压电薄膜表面的平行电极激发,三周期的1/4波长SiO2/W层交替排列构成了布拉格反射层.通过有限元分析计算了电场分布,设计了平行电极参数.结果表明:AlN薄膜具有良好的c轴择优取向,器件实现了稳定的2 GHz频率的单纯剪切波谐振,器件的品质因数Qs和Qp分别为434和393,等效机电耦合系数K2eff为0.97%,有效的横向电场激励和布拉格反射层的选频作用对纵波的抑制明显.这种谐振器非常有利于作为在液体环境中工作的生化传感器.Thin film bulk acoustic resonators operated in shear mode have promising applications in biochemical sensors.The shear mode AlN solid mounted resonator using lateral field excitation was presented.The resonator configuration consists of the highly c-oriented AlN piezoelectric film,the parallel electrodes on the film surface and the three-period SiO_2/W acoustic Bragg reflector.The electric field characteristics were calculated by finite element modeling in order to design the electrode frame.The testing results of the finished device show that the pure shear mode wave can be excited at 2 GHz.The quality factor （Q_（s） and Q_p） and the effective electromechanical coupling content （K^2_（eff）） is 434,393 and 0.97 %,respectively.The longitudinal wave is restrained by the effective lateral electric field and the frequency selectivity of the acoustic reflector.

关 键 词：薄膜体声波谐振器 剪切波模式 ALN薄膜 

分 类 号：TN015[电子电信—物理电子学] TN384