白光干涉检测仪垂直扫描系统设计

白光垂直扫描干涉测量方法具有高精度、大量程并且为非接触测量等优点,因此被广泛地应用于半导体、微机电系统(MEMS)等检测领域.传统的白光扫描干涉仪采用压电(PZT)陶瓷驱动器,虽然能实现高精度的测量,但存在量程小、测量效率低等缺点.基于此,提出了以步进电机作为驱动器、高精度光栅尺作为位置反馈的白光干涉垂直扫描运动平台,并设计了以现场可编程逻辑门阵列(FPGA)为核心处理器的控制板卡.实验证明,该运动平台在运动速度为50 μm/s时,定位偏差小于15 nm,最大行程为3 mm,实现了高精度、大行程以及高效率的扫描检测.可以以较低的成本实现对具有高深宽比的微纳器件形貌的检测.

Design of a Vertical Scanning System for White Light Interferometers

White light vertical scanning interferometry method is widely used in semiconductor testing field and micro-electro mechanical systems (MEMS) testing field due to its high precision,large range and a non-contact measurement,etc.The conventional white light interferometer using piezoelectric (PZT) ceramic actuator,although able to achieve highly accurate measurements,there are still some shortcomings such as smallscale,low measuring efficiency.Based on this,a white light interference vertical scanning motion platform with a stepper motor as the driver and high-precision grating scale as position feedback grating was proposed,and the control board with field programmable gate arrays (FPGA) as the core processor was designed.Experiments show that when the velocity of the moving platform is 50 μm/s,the positioning accuracy is 15 nm,and the maximum stroke is 3 mm,achieving a scan detection with high precision,large stroke and high efficiency.The morphology of micro-nano devices with high aspect ratio can be tested at a low cost.