基于高阶谐振悬臂的轻敲式原子力显微镜测量特性  

Measurement Characteristics of Tapping-Mode Atomic Force Microscope Based on Higher-Order Resonant Cantilever

作　　者：赵阳[1,2] 黄强先[1] 张蕤[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230601

出　　处：《纳米技术与精密工程》2016年第3期223-228,共6页Nanotechnology and Precision Engineering

基　　金：国家自然科学基金资助项目(51175141);安徽省高等学校省级自然科学基金资助项目(KJ2015JD09)

摘　　要：轻敲式原子力显微镜的悬臂为无限自由度系统,具有多阶谐振模态.为了提高动态原子力显微镜的测量特性,采用激励硅悬臂工作于高阶谐振模态的方法.相较于基础模态,高阶谐振悬臂的振动频率和品质因数有所提高,结合振型的不同以及光杠杆检测法的特性,从理论上对高阶谐振模态下动态原子力显微镜的测量特性进行了分析.构建了基于高阶谐振的动态原子力显微镜系统,围绕其主要测量特性,如表面探测垂直分辨力、时间扫描速度以及阻尼特性进行了研究和测试,理论分析和实验结果均表明,相较于一阶谐振模态,二阶谐振模态下的动态原子力显微镜系统的测量特性得到了提高:二阶谐振悬臂扫描速度约为一阶谐振悬臂的3.3倍;二阶谐振悬臂的探测垂直分辨力可达到0.5 nm,远远优于一阶悬臂的0.9 nm;并且二阶谐振悬臂的品质因数远高于一阶谐振状态,降低了大气阻尼对悬臂系统的影响.The cantilever of tapping-mode atomic force microscope （ AFM） is a system with infinite de-gree of freedom and has many resonant modes. In order to enhance the measurement characteristics of AFM, the cantilever is excited to work at the higher-order resonance. Due to the increase in frequency and quality factor, the different vibration mode of the higher-order resonant cantilever and the characteris-tic of optical lever detection, the measurement characteristics of the dynamic AFM are analyzed compared to the fundermental resonance. The tapping-mode AFM system based on higher-order resonance was built and its measurement characteristics including the flexural sensitivity, scanning speed and damping char-acteristic were tested. Theoretical analysis and experimental results demonstrate that the measurement characteristics of dynamic AFM of the second-order resonant cantilever are improved compared with that of the AFM operated in the first order. The scanning speed of the second-order resonant cantilever is about 3. 3 times higher than that of the first-order resonant cantilever;the flexural sensitivity of the second-order resonant cantilever is improved to 0. 5 nm while that of the first-order resonant cantilever is 0. 9 nm; the quality factor of the second order is much higher than the first order so that the damping effect to the AFM is decreased.

关 键 词：高阶谐振 垂直分辨力 阻尼系数 扫描速度 原子力显微镜 

分 类 号：TH742[机械工程—光学工程]