基于白光干涉的MEMS三维表面形貌测量

利用白光干涉垂直扫描原理,设计了测量微机电系统(MEMS)表面形貌特征的垂直扫描白光干涉系统.该系统由垂直扫描位移工作台驱动被测件,通过检测被测件表面的干涉条纹变化得到表面形貌.垂直扫描位移工作台利用压电陶瓷驱动柔性铰链结构进行纳米驱动,光栅传感器监控整个垂直扫描过程,对压电陶瓷的非线性误差进行实时补偿.垂直扫描位移工作台的性能分析表明:分辨率达到1 nm,定位精度小于10 nm.同时采用图像分析技术对光学仪器测量台阶出现的噪声进行了消噪处理,试验结果表明垂直扫描白光干涉系统能够实现MEMS三维表面形貌的高精度测量.

MEMS profile measurement by white-light interferometry

A vertical scanning white-light measurement system was designed to measure the profile characteristic of micro electro mechanical systems(MEMS) based on vertical scanning white-light interferometric measurement principle.The surface profile was calculated by detecting the white-light interference fringe of the measured surface during the process the measured moves with the vertical scanning displacement stage.A mechanism of flexural-hinge guided motion micro-displacement is utilized and driven by piezoelectric transducer(PZT) in this stage,and the vertical scanning process is monitored by grating sensor,which compensate the non-linear error caused by PZT in real-time.The performance analysis of vertical scanning displacement stage shows that its resolution is 1 nm and its precision is less than 10 nm.The image analysis technique is also utilized to reduce the noise caused by the limitation of interferometric microscope when step surface is measured,and its experiment results show that this system excellently achieves the precise measurement for the profile characteristics of MEMS.