基于ScAlN/FeGa结构的磁电声表面波谐振器

Magnetoelectric Surface Acoustic Wave Resonator Based on ScAlN/FeGa Structure

该文研究基于磁致伸缩FeGa合金衬底的磁电声表面波(SAW)谐振器。首先,在FeGa磁致伸缩衬底上溅射沉积了ScAlN压电薄膜,完成了单端口声表面波谐振器的制备;其次,采用X线衍射仪(XRD)、扫描电子显微镜(SEM)、原子力显微镜(AFM)等手段对ScAlN薄膜进行结构分析;最后,采用矢量网络分析仪和微波探针台测试S参数和群时延。结果表明,ScAlN薄膜晶粒呈柱状生长且具有高度(002)取向,薄膜表面粗糙度在2.36nm左右;当ScAlN压电薄膜厚为0.7μm,波长为15.74μm时,SAW谐振器的谐振频率为218.75 MHz,相速度为3 443m/s,机电耦合系数为0.06%,与COMSOL仿真计算结果较吻合。

A magnetoelectric surface acoustic wave (SAW) resonator based on FeGa alloy magnetostrictive substrate has been investigated in this paper. First, the ScAlN piezoelectric film was deposited by RF reactive magnetron sputtering on FeGa alloy magnetostrictive substrate and the one-port SAW resonator was fabricated. Then the structure analysis of ScAlN thin films was carried out by XRD, SEM and AFM. Finally, the S 11 parameter and group delay were measured by the vector network analyzer and microwave probe station. The results show that the ScAlN thin film has a columnar growth and a high (002) orientation, and the film surface roughness (RMS) is about 2.36 nm. When the thickness of the ScAlN piezoelectric film is 0.7 μm and the wavelength is 15.74 μm, the resonant frequency of SAW resonance is 218.75 MHz, the phase velocity is 3 443 m/s, and the electromechanical coupling is 0.06%, which is in good agreement with the COMSOL simulation results.