光学精密工程2024，Vol.32Issue(7)：956-965,10.DOI:10.37188/OPE.20243207.0956
高精度激光共焦半导体晶圆厚度测量
High-precision laser confocal measurement of semiconductor wafer thickness
摘要
Abstract
Addressing the need for precise non-contact measurement of semiconductor wafer thickness,this study introduces a method based on laser confocal technology that ensures remarkable accuracy.It uti-lizes a voice coil nanodisplacement platform for high-resolution actuation of a laser confocal optical probe,enabling precise axial scanning.This method relies on identifying the peak points on the confocal laser's axi-al response curve,which are indicative of the objective lens's focal point,to accurately align and position the wafer's upper and lower surfaces.By accurately calculating the physical coordinates of each sampling point on the wafer surface through ray tracing algorithms,this technique achieves high-precision non-contact measurement of wafer thickness.A specialized laser confocal sensor for semiconductor wafer thick-ness measurement was developed,showcasing an axial resolution of under 5 nm,an axial scanning range of up to 5.7 mm,and repeatability in thickness measurement of under 100 nm across six wafer types.The process takes less than 400 ms for a single wafer.This research successfully applies confocal focusing tech-nology to semiconductor measurement,offering a novel solution for high-precision,non-destructive,on-line wafer thickness measurement.关键词
激光共焦/厚度测量/半导体晶圆/光线追迹/高精度/无损测量Key words
laser confocal/thickness measurement/semiconductor wafer/high precision/nondestruc-tive measurement分类
电子信息工程引用本文复制引用
李兆宇,刘子豪,王瑶莹,邱丽荣,杨帅..高精度激光共焦半导体晶圆厚度测量[J].光学精密工程,2024,32(7):956-965,10.基金项目
国家自然科学基金联合基金集成项目(No.U22A6006) （No.U22A6006）
