基于FPGA的CMP电涡流终点检测装置设计  

Design of the Eddy Current End Point Detection Instrument During CMP Process Based on FPGA

作　　者：吴旭[1] 王东辉[1] 杨元元[1] 

机构地区：[1]中国电子科技集团公司第四十五研究所,北京100176

出　　处：《计算机测量与控制》2017年第4期28-30,39,共4页Computer Measurement &Control

基　　金：02重大科技专项(2015ZX02101)

摘　　要：为实现对晶圆表面金属层的化学机械抛光(CMP)过程中的终点检测和对抛光速率进行监控的要求,设计了一种基于电涡流测量原理的测量装置;该装置以FPGA器件作为控制核心,由其控制高速D/A转换器生成正弦交流信号,并驱动测量电桥;由于测量线圈产生的交变磁场在晶片金属薄膜上产生电涡流,引起测量线圈的阻抗发生变化;通过测量相应的阻抗变化产生的信号,可以计算出相应的晶片表面金属薄膜的厚度;实验表明该装置可以满足对晶圆表面100~1 000nm厚度金属层的测量要求。A Eddy current measuring instrument is designed for end point detection and monitoring the removal rate of metal layer on wafer during chemical and mechanical planarization process. The sine signal generated by high speed D/A convertor the FPGA device controlled drives the circuit bridge. The impedance of the coil changes because of the effect of eddy current the alternate magnetic field of measurement coil induced. The signal produced by the impedance changing of the coil is measured and the thickness of the metal on wafer is computed. The thickness of metal film on wafer is measured with the signal of coil impedance being acquired. The experimental result indicate this instrument is able to measure the 100-1000nm metal film on wafer.

关 键 词：电涡流 化学机械抛光 锁定放大器 FPGA 

分 类 号：TP274[自动化与计算机技术—检测技术与自动化装置]