AlN薄膜体声波谐振器性能分析

采用体硅微细加工工艺制备了背空腔型AlN薄膜体声波谐振器。研究了压电层、上电极及支撑层厚度对谐振器性能的影响。测试结果表明,谐振器所用AlN压电薄膜具有(002)择优取向,器件频率特性良好。当上电极、压电层、底电极和支持层的厚度分别为110,2600,110,200nm时,谐振频率为1.759GHz,机电耦合系数3.75%,品质因数79.5。结合Mason等效电路模型模拟分析与实验结果,分析了各层厚度对频率特性的影响机理。

Characteristics of the AlN film bulk acoustic resonators

Back-etching type AlN film bulk acoustic resonators were fabricated using silicon bulk micromachining technique. The characteristics of the resonators varied in the thickness of the piezoelectric films, top electrodes or membranes were analyzed. The measurement results show that the AlN piezoelectric films, applied to the devices, are featured in (002) preferred orientation. The fabricated FBARs exhibited significant frequency performance, when the thickness of the top electrodes, piezoelectric films, bottom electrodes and membranes are 110, 2 600, 110, 200 nm, the resonant frequency of 1.759 GHz, the effective coupling coefficient of 3.75%, and quality factor of 79.5. Combine the simulated results according to the Mason model and the experiment result, the effect of the thickness to the frequency characteristics was specified.