小型自感应原子力显微镜测头及其标定  

Development and Calibration of Compact Self-Sensing AFM Head

作　　者：赵健[1] 郭彤[1] 马龙[1] 傅星[1] 胡小唐[1] 

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072

出　　处：《纳米技术与精密工程》2011年第2期168-173,共6页Nanotechnology and Precision Engineering

基　　金：科技部国际科技合作与交流项目(2008DFA71610);国家自然科学基金资助项目(91023022;60723004)

摘　　要：设计了一种小型轻敲式自感应原子力显微镜(AFM)测头以实现微/纳尺度下的几何量测量.轻敲式测头采用石英音叉式自感应探针,通过自身的电信号输出检测悬臂梁的振幅变化,无需额外的光学传感器.设计了测头的微弱自感应信号放大电路,并补偿音叉寄生电容对测量的干扰.机械结构紧凑便于将测头固定于光学显微镜下观察测量情况,同时屏蔽外界的干扰.利用显微激光多普勒测振系统,标定了测头机电耦合系数为145 nm/V,由此可以计算测头工作频率下悬臂梁的振幅.搭建了以纳米测量机(NMM)为高精度定位平台的测试系统,利用该系统对测头进行进/退针实验,标定测头的灵敏度为0.47 nm/mV,NMM内置的干涉仪保证标定直接溯源至"米"定义.实验表明测头的非线性误差小于1%,测量范围在百纳米级.A compact tapping mode self-sensing atomic force microscope（AFM） head was developed for the micro-nano dimensional measurement.A quartz tuning fork self-sensing probe was integrated into the head which could use its electrical signal to detect amplitude variations of the cantilever and did not need any external optical sensor.A signal detection circuit was conceived to amplify the weak current in the probe and to compensate for the inherent capacitance of the quartz tuning fork.A compact mechanical design has been realized to assemble the head under the microscope objective for the inspection of measurement situation and to shield outside interference.Several measurements were designed to calibrate the electro-mechanical coupling factor and sensitivity of the head.By means of the micro laser doppler system,the electro-mechanical coupling factor of head was calibrated as 145 nm/V,according to which the resonance amplitude of the cantilever in free space could be calculated.An experimental system was established based on the high precision positioning stage of nano-measuring machine（NMM）,with which the approach/retract tests were carried out to calibrate the sensitivity of the head as 0.47 nm/mV.The tests could be traced to the meter definition by interferometers in NMM.Besides,experimental results indicate that the non-linearity error of the AFM head is less than 1% and the measurement stroke is on the level of hundreds of nanometers.

关 键 词：原子力显微镜(AFM)测头 轻敲模式 自感应探针 机电耦合系数 高精度定位平台 

分 类 号：TH742[机械工程—光学工程]