体声波复合谐振器新结构的研究

Study on a Novel Structure for Bulk Acoustic Wave Composite Resonator

本文报道了一种由氧化锌薄膜和多晶硅膜片构成的体声波复合谐振器的新结构，与传统制作在硅支撑膜片上的压电复合谐振器不同，多晶硅支撑膜采用表面微机械技术获得，因而是完全平面工艺，不需要双面光刻和背面腐蚀。采用Ｓ枪磁控反应溅射在多晶硅膜片上获得了ｃ轴取向良好的氧化锌薄膜。所得的谐振器的基波工作频率在５６０ＭＨｚ左右，而尺寸小于２５０×２５０μｍ２。

This paper reported a novel bulk acoustic wave (BAW) microresonator structure based on piezoelectric thin films and polysilicon membrane. In contrast with conventional BAW composite resonators based on Si membrane,the poly-Si mambrane is fabricated with surface micromachining technology. The process is a completely planar approach and the double-side lithography and back-side etch are deleted. The c-axis oriented piezoelectric thin film ZnO is grown on poly-Si membrane by S-gun magnetron reactive sputtering.The size of a microresonator is less than 250×250μm2 and the resonant frequency is about 560MHz.