Aluminum Nitride Thin Films on Molybdenum/Polyimide Heterostructure for Bulk Acoustic Resonators

摘要:

采用中频反应磁控溅射方法，在钼/聚酰亚胺/硅 (Mo/PI/Si)基片上室温下制备出c轴取向柱状结晶氮化铝(AlN)薄膜，X射线衍射摇摆曲线和拉曼谱E2(高)峰半高宽分别是2.2°和18.6?cm-1。制作了基于Mo/AlN/Mo/PI/Si结构的薄膜体声波谐振器(FBARs)，PI/Mo异质结用作声绝缘层。用矢量网络分析仪分析了FBARs的谐振特性，器件等效耦合系数达到5.4%。

Abstract:

The c-axis textured aluminum nitride (AlN) thin films with columnar grains perpendicular to Molybdenum(Mo)/ Polyimide(PI)/Si(111) substrate could be obtained through reactive magnetron sputtering at room temperature. The full width at half maximum of the X-ray diffraction rocking curves and E2 (high) peak of Raman spectrum of the AlN thin films were 2.2° and 18.6?cm-1, respectively. The thin film bulk acoustic resonators (FBARs) with Mo/AlN/Mo/PI/Si (111) configuration were fabricated, and a PI/Mo heterostructure was used as acoustic isolation layer for the FBARs. The resonant frequency response of the FBARs was measured using a vector network analyzer, and an effective coupling coefficient of 5.4% was achieved.