基于双反馈模式的大范围自感应AFM测量系统

Large Range Self-sensing AFM Measurement System Based on Dual Feedback Measurement Model

为了提高原子力显微镜（AFM）的测量范围，设计了一种基于双反馈测量模式的大范围自感应原子力显微镜系统，测量系统中有两条反馈回路：一条反馈回路由压电陶瓷与AFM测头组成，动态响应较快的压电陶瓷位移台的运动量可以表征被测样品表面的高频信息；另一条反馈回路由压电陶瓷位移台和纳米测量机（NMM）的反馈控制器组成，利用压电陶瓷位移台的位移信号控制NMM运动，NMM的mm级=向测量范围使得被测样品较大变化范围的低频轮廓信息很容易地被表征出来。使用本系统对平面样品和一维栅格进行了测量实验，实验结果表明采用双反馈的测量模式的AFM测量系统能够有效地表征被测样品的低频轮廓信息和表面高频信息，测量范围能够达到mm级，纵向分辨率达到nm级，具有良好测量重复性。

A large range self-sensing AFM measurement system based on dual feedback measurement model was designed. The purpose is to improve the AFM measurement range. The self-sensing AFM system has two feedback loops ： one is composed by piezoelectric ceramic transformer （PZT） and AFM measurement head. The fast dynamic response of the PZT displacement platform can characterize high frequency information of the sample surface; another loop is PZT displacement platform and the nano measuring machine （NMM） feedback controller. The PZT displacement stage position signal controls the NMM movement, and NMM millimeter z direction measurement range makes wide variation range low frequency contour information of the samples easily be characterized. By the system ,fiat samples and one-dimensional lattice are measured by experiments, the experimental results show that using dual feedback AFM measurement system can effectively characterize the sample frequency contour information and surface high frequency information, measurement range can reach millimeter level, the longitudinal resolution reaches nanometer level and the measurement repeatability is good.