摘要
一定厚度的低声阻抗支撑层可以在薄膜体声波谐振器(FBAR)与衬底之间形成声学隔离层,防止声波泄漏到衬底当中。掺碳二氧化硅(CDO)是一种低声阻抗材料,对FBAR具有较好的温度补偿效果,可以作为FBAR与衬底之间的声学隔离层,从而构成一种新型的CDO-FBAR。为了分析CDO-FBAR与通孔型FBAR相比性能是否退化,以及CDO声学隔离层所需厚度,采用多物理场耦合仿真软件分析了CDO-FBAR和通孔型FBAR的谐振频率、Q值、有效机电耦合系数和S参数,并提取了CDO-FBAR纵向振动位移。分析结果表明:CDO-FBAR的谐振频率整体向下漂移;CDO声学隔离层导致S参数的寄生干扰;由于声学损耗增加,Q值略有降低,其中并联谐振点处的Q值降幅更大;有效机电耦合系数略有降低;声波传播到声学隔离层中9μm处就完全衰减,即只需要9μm厚的CDO声学隔离层就能在FBAR与衬底之间形成有效的声学隔离。由此,仿真验证了这种新颖的CDO-FBAR结构的可行性。
Low acoustic impedance support layer with a certain thickness between film bulik acoustic resonator （FBAR） and the substrate can form an acoustic isolation layer to prevent sound leakage to the substrate. Carbon-doped oxide（CDO） is a kind of low acoustic impedance material with good temperature compensation for FBAR, and it can be used as acoustic isolation layer between FBAR and the substrate which results in a novel FBAR structure named as CDO-FBAR. In order to analyze whether the properties of CDO FBAR is degenerated compared with via-hole type FBAR and the required thickness of CDO as acoustic isolation layer, we used multi-physics coupled simulation software to analyze the resonant frequency, the Q （quality factor） value, the effective electromechanical coupling coefficient and S parameter of the two kinds of FBARs, and to extract longitudinal vibration displacement of CDO FBAR. The results indicate： the overall resonant frequency of CDO-FBAR is downshift; CDO isolation lay er induced parasitic disturbance in S-parameter; because of the increasing acoustic loss, the Q value decreased slightly, and more reduction happened at parallel resonant frequency; and the effective electromechanical coupling coefficient has also reduced slight ly; acoustic wave did not completely attenuate until sound wave propagating in the acoustic isolation layer for 9 μm, i.e. it needs only 9 μm thick CDO material to form an effective acoustic isolation layer between FBAR and the substrate. Thus, the feasibility of the novel CDO-FBAR structure is verified by simulation.
出处
《强激光与粒子束》
EI
CAS
CSCD
北大核心
2016年第10期88-92,共5页
High Power Laser and Particle Beams
基金
国家自然科学基金项目(61574131)
中国工程物理研究院超精密加工技术重点实验室基金项目(2014ZA001)
中国工程物理研究院电子工程研究所创新基金项目(S20141203)
核探测与核电子学国家重点实验室开放课题基金项目(2016KF02)
西南科技大学特殊环境机器人技术四川省重点实验室开放基金项目(14zxtk01)
西南科技大学研究生创新基金项目(15ycx122,15ycx123,15ycx125)
关键词
声阻抗
掺碳二氧化硅
薄膜体声波谐振器
声学隔离层
acoustic impedance
carbon doped oxide
oxide-film bulk acoustic resonator
acoustic isolation layer
