动态AFM悬臂的高阶谐振特性研究及实验  

Research and experiment on higher-order resonance characteristic of dynamic AFM cantilever

作　　者：黄强先[1] 袁丹[1] 尤焕杰[1] 赵阳[1,2] 程真英[1] 

机构地区：[1]合肥工业大学仪器科学与光电工程学院,合肥230009 [2]安徽建筑大学电子与信息工程学院,合肥230061

出　　处：《仪器仪表学报》2013年第12期2647-2652,共6页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(50975075)资助项目

摘　　要：为了提高动态原子力显微镜(AFM)的灵敏度、分辨率、扫描速度等,基于硅悬臂器件具有多阶谐振模态的特性,提出一种利用硅悬臂高阶谐振而进行扫描测量的高阶谐振表面测量方法,并对相应动态AFM悬臂的高阶谐振特性进行了理论和实验研究。分析了高阶谐振悬臂的工作原理,给出了悬臂的振动方程和振型函数,从理论上证明了高阶谐振悬臂较其初级谐振模式具有更高灵敏度和更高空间分辨率;由于频率的提高,悬臂的动态测量性能明显改善。基于自制的轻敲式AFM,通过实验证实了高阶谐振现象的存在;实验测得的一阶二阶谐振悬臂的灵敏度,空间分辨率和最小可探测力梯度分别为8 V/μm,17 V/μm;1.33 nm,0.47 nm;1.80×10-7N/m,0.54×10-7N/m,实验结果与理论分析结论一致;通过二阶谐振扫描获得了光栅试样表面轮廓图,证明了该高阶谐振特性研究的正确性及利用高阶谐振特性进行扫描测量的可行性。In order to improve the sensitivity,spatial resolution,and scanning speed of the dynamic atomic force mi- croscope （AFM）,based on the higher-order resonance mode characteristic of the silicon cantilever, a kind of new surface measurement method is put forward, which makes use the higher order resonance characteristic of the silicon cantilever to perform scanning measurement;and the theoretical and experimental research on the higher-order reso- nance characteristic of the corresponding dynamic AFM cantilever are carried out. The operation principle of the high- er-order resonance cantilever is analyzed, and the vibration equation and vibration mode function of the cantilever are given. It is theoretically proved that the higher-order resonance cantilever has higher sensitivity and higher spatial res- olution compared with the primary resonance mode cantilever;and the dynamic measurement performance of the can- tilever is significantly improved due to the increasing of the frequency. Based on the self-made tapping-mode AFM, the existence of the higher-order resonance phenomenon was verified through experiments. The sensitivity, spatial res- olution, and minimum detectable force gradient of the first and second order resonance cantilevers measured in the ex- periments are 8 V/μm,17 V/μm;1.33 nm,0.47 nm;1.80 × 10 ^-7 N/m,0.54 × 10^ -7 N/m,respectively;and the ex- perimental results are consistent with the theoretical analysis conclusion. The surface profile of a grating sample is ob- tained with the second resonance scanning, which proves the correctness of the research on higher-order resonance characteristic and the feasibility of the scanning measurement using higher-order resonance characteristics.

关 键 词：硅悬臂 高阶谐振 动态AFM 最小可探测力梯度 

分 类 号：TH89[机械工程—仪器科学与技术] TH71[机械工程—精密仪器及机械]