基于ZYNQ的用于间隙测量的白光干涉信号处理系统

White Light Interference Signal Processing System for Gap Measurement Based on ZYNQ

为实现在表面等离子体光刻机中对掩模与基片间的间隙测量,提出一种基于白光干涉测量技术的掩模-基片间隙测量方法,并设计了以ZYNQ芯片为核心的信号处理系统。以ZYNQ芯片的片上ARM用作参数设定、驱动控制以及前端显示,以可编程逻辑资源用于实现光谱数据的小波处理和互相关解调。系统以分布并行结构运行,大大提高了测量速度,并实现了对掩模-基片间隙的实时测量。最后为了确定测量精度,搭建了激光干涉仪精度测试平台。测试实验表明,间隙测量的重复测量精度为4.4 nm,位移测量精度为6.7 nm,满足间隙测量性能稳定和精度高等要求。

In order to realize the gap measurement between the mask and the substrate in the surface plasma lithography machine,a gap measurement method of the mask-substrate gap was proposed based on white light interferometry,and a signal processing system was designed based on ZYNQ.ZYNQ’s on-chip ARM was used for parameter setting,drive control,and front-end display. The programmable logic resources were used to realize wavelet processing and cross-correlation demodulation of spectral data. This system operated in a distributed parallel structure,which could greatly improve the detection speed,and realize the real-time measurement of the mask-substrate gap. Finally,in order to determine the measurement accuracy,a laser interferometer accuracy test platform were built.Test experiments showed that the repeat measurement accuracy was 4.4 nm,and the displacement measurement accuracy was 6.7 nm. It could satisfy the gap measurement system requirements of stabilization and higher precision.