ZnO/蓝宝石结构声表面波滤波器试验研究

An Experimental Study on SAW Filter with ZnO/Sapphire Structure

该文从理论上计算得到了ZnO(a面)/蓝宝石(r面)结构的声表面波相速度和机电耦合系数色散曲线。依据该色散曲线设计了ZnO(a面)/蓝宝石(r面)结构声表面波滤波器。采用在蓝宝石衬底上先制备ZnO薄膜然后再制作芯片结构的方案研制出了声表面波器件样品。研制过程中生长出了a面结构的ZnO薄膜,其中厚膜样品测试得到了3种声波模式,即模式0、1及2,模式0、1和2的频率分别为1 073.79 MHz,1 290.63 MHz和1 572.3 MHz,因此,间接测得了模式0、1和2的相速度分别为3 865.67m/s,4 646.25m/s和5 660.27m/s。

The dispersion curves（phase velocity and electromechanical coupling coefficient）of ZnO（aplane）/sapphire（r plane）structure are obtained by theoretical calculation.A SAW filter with ZnO/sapphire structure is designed based on the calculating results.The SAW filter prototype is fabricated by depositing ZnO film on sapphire substrate and then fabricating chip.In the process,the a-plane ZnO thin film has been grown.Three SAW modes of the thick film sample,named mode 0,mode 1and mode 2,are measured.The measured center frequency of mode 0and mode 1and mode 2is 1 073.79 MHz,1 290.63 MHz and 1 572.3 MHz respectively.The measured phase velocity of mode 0and mode 1and mode 2is 3 865.67m/s,4 646.25m/s and 5 660.27m/s respectively.