[关键词]
[摘要]
利用有限元方法分析了基于IDT/ZnO/AlN/Diamond不同结构混合SAW/BAW 器件的声学特性,包括层状薄膜结构、ZnO 薄膜刻蚀结构和填充结构。结果表明,当hZnO/λ=0.3、hAlN/λ=0.5,且ZnO 被完全刻蚀(d/hZnO=1)时,刻蚀结构混合SAW/BAW(准西沙瓦波)的机电耦合系数(K2)取得最大值6.54%,比层状结构(d/hZnO=0)提升了近一倍。刻蚀结构中,SiO2 和Diamond填充物的引入不仅提高了准西沙瓦波的K2,而且改善了其压力传感特性。当d/hZnO =1时,SiO2 和Diamond填充结构准西沙瓦波的压力频移分别为81.2 kHz/MPa和207.4 kHz/MPa,比刻蚀结构分别提高了58.7%和300%;同时,Diamond填充物的引入使准西沙瓦波的频率压力系数(PCF)达到最大值297×10-6/MPa,比d/hZnO=0时提高了约30%。由此可知,通过引入不同的填充物可以开发不同的功能传感器,在压力、温度和气敏等传感领域将具有极大的应用前景。
[Key word]
[Abstract]
The acoustic characteristics of hybrid SAW/BAW devices based on IDT/ZnO/AlN/Diamond with
layered, etched, and filled structures are investigated using finite element methods.The results indicate that when
hZnO/λ=0.3, hAlN/λ=0.5, and the ZnO piezoelectric film is completely etched (d/hZnO =1), a maximum K2 of
6.54% is obtained for the hybrid SAW/BAW (named quasi-Sezawa wave) excited in etched structure, which is
nearly two times that of the layered SAW structure (d/hZnO =0).The K2 and pressure sensing properties of the
quasi-Sezawa devices are further improved by introducing SiO2 and Diamond fillings.As d/hZnO =1, the pressure
frequency shifts of the quasi-Sezawa device with SiO2 and Diamond fillings are 81.2 kHz/MPa and 207.4 kHz/MPa,
respectively, which are 58.7% and 300% higher than those of the etched structure.Meanwhile, the frequency pressure
coefficient (PCF) of the quasi-Sezawa device with Diamond fillings is 297×10-6/MPa, which is approximately
30% higher than that of the layered SAW structure.It can be concluded that different function sensors based on the
hybrid SAW/BAW can be developed by introducing different fillings.This can have important application prospects
in the fields of pressure, temperature and gas sensing sensors.
[中图分类号]
[基金项目]
江苏省研究生科研创新计划(KYCX21_0711)；南京邮电大学基金资助项目(NY213038)
