摘要
铌酸锂(LN)单晶薄膜具有较高的机电耦合系数(k_(eff)^(2)>30%),其水平剪切(SH)声学模式常被应用于开发具有大机电耦合系数的薄膜声学谐振器和超宽带滤波器。但LN的频率温度系数较大(TCF>-50×10^(-6)/℃),这不仅会降低滤波器的可用有效带宽,同时也会限制器件的功率处理能力。采用3D周期有限元模型对基于X切LN/SiO2/Si结构SH声表面波(SH-SAW)谐振器进行了优化研究。研究结果表明,当SH-SAW传播角ψ=-10°~-20°、LN和SiO2膜厚分别为hLN=0.1λ和hSiO_(2)=0.2λ(λ为叉指换能器周期)、铝电极金属化率η=0.4、电极相对厚度hAl/λ=5%~10%时,SH-SAW谐振器的k_(eff)^(2)约为30%,且其TCF<-20×10^(-6)/℃,有望用于开发新一代的低温漂、超宽带5G SAW滤波器。
Owing to its high electromechanical coupling coefficient(k_(eff)^(2)>30%),the horizontal shear(SH)acoustic modes in lithium niobate(LN)single-crystal films are typically investigated to develop thin-film acoustic resonators with large electromechanical coupling and ultra-wideband acoustic filters.However,its temperature coefficient of frequency(TCF)is extremely high(>-50×10^(-6)/℃).A high TCF not only reduces the effective bandwidth but also limits the power-management capability of the filters.Herein,we present an investigation into the optimization design of a low drift,large electromechanical coupling horizontal-shear surface acoustic wave(SHSAW)resonator based on the X-cut LN/SiO2/Si structure using a three-dimensional periodic finite-element model.Simulation results show that when the SH-SAW propagation angleψis between-10°and-20°,the film thicknesses of LN and SiO_(2)are 0.1λand 0.2λ(whereλis the period of the interdigital transducer)respectively,the metallization rate of the aluminum electrode(η)is 0.4,the relative thickness of the electrode is between 5%and 10%,the k_(eff)^(2)of the SH-SAW resonator remains at~30%,and the TCF is less than-20×10^(-6)/℃.Hence,the resonator is suitable for developing the next generation of low-temperature drift,ultra-wideband 5G SAW filters.
作者
温福军
王园园
钱莉荣
王荔田
李翠平
熊阳
田亚会
李红浪
WEN Fujun;WANG Yuanyuan;QIAN Lirong;WANG Litian;LI Cuiping;XIONG Yang;TIAN Yahui;LI Honglang(Tianjin Key Laboratory of Film Electronic&Communication Devices,School of Integrated Circuit Science and Engineering,Tianjin University of Technology,Tianjin 300384,China;Engineering Research Center for Optoelectronic Devices and Communication Technology of Ministry of Education,Tianjin University of Technology,Tianjin 300384,China;Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China;National Center for Nanoscience and Technology,Beijing 100190,China)
出处
《压电与声光》
CAS
北大核心
2024年第3期290-295,共6页
Piezoelectrics & Acoustooptics
基金
国家重点研发计划项目(2022YFB3606702)
广东省重点研发计划项目(2023B0101190002)
广州市重点研发计划项目(202206070001)
天津市技术创新引导专项(基金)企业科技特派员项目(23YDTPJC00600)
北京市科技新星计划项目(20220484172)
中国科学院青年创新促进会(2022024)。
