Micro-LED晶圆缺陷检测的宽光谱大视场显微物镜设计  

Design of Microscopic Objective with Wide-spectrum and Large Field of View for Micro-LED Wafer Defects Detection

作　　者：洪惠敏 贺文俊[1] HONG Huimin;HE Wenjun(Changchun University of Science and Technology,School of Optoelectronic Engineering,Changchun 130022,China)

机构地区：[1]长春理工大学光电工程学院,长春130022

出　　处：《光子学报》2025年第3期207-220,共14页Acta Photonica Sinica

基　　金：吉林省自然科学基金(No.20240101341JC)。

摘　　要：为了实现对Micro-LED晶圆缺陷的准确和高效检测,设计了一款工作波长覆盖可见光和近红外的宽光谱、大视场、平场、复消色差显微物镜。采用正-正-负三光组结构,计算调整了各光组光焦度并分配其元件特征,实现了大视场和长工作距设计。基于Buchdahl色散模型进行了玻璃材料的色散矢量分析并指导了初始光学系统材料替换,实现了平场复消色差设计。设计结果表明:该显微物镜的工作波长范围为420 nm~1064 nm、放大倍率为10倍、视场为3.3 mm、数值孔径为0.34、可见光波段分辨率为0.88μm、近红外波段分辨率为1.35μm、工作距为8 mm、齐焦距为95 mm。其成像质量优良,调制传递函数曲线接近衍射极限,全谱段复消色差,全视场平坦,易于加工生产,可用于检测大范围的表面以及次表面的微米级Micro-LED晶圆缺陷。Micro-LED,renowned for its exceptional brightness,energy efficiency,and rapid response times,has shown immense potential in the display technology sector,particularly in light of the ongoing advancements within the semiconductor industry.The detection of defects in the wafer is a crucial step in the production of Micro-LED,as it guarantees the dependability and excellence of the final product.The core technology underpinning the wafer defects detection system,which is microscopic visual online inspection,aids in the stable detection of product defects.Regrettably,the limitations in spectral range,field of view,and spatial resolution of current commercial microscopic objectives present a significant challenge in meeting the stringent high-precision and rapid detection demands for Micro-LED wafer defects.Based on our analysis of the system's operational requirements,the microscopic objective for the automatic optical inspection system intended for detecting defects in Micro-LED wafer must encompass a wide spectral range,offer a large field of view,achieve high spatial resolution,and maintain a considerable working distance.We established the design specifications and selected the camera based on the resolution and field of view criteria of the microscopic objective,aligning with international standards for microscopic objective.Considering the design priorities of a large field of view and a long working distance,the microscopic objective is structured as a retro-telecentric system,comprising three optical groups with positive,positive,and negative focal lengths for the front,middle,and rear groups,respectively.The angle ratios between the optical groups were established asΔu_(1):Δu_(2):Δu_(3)=0.8∶0.7∶-0.5,in order to minimize the considerable light deviation between lenses and to ease the structural design and adjustment.Utilizing the multi-group combination calculation formula,we calculated the focal lengths of the optical groups to beφ_(1)=0.025 mm^(-1),φ_(2)=0.020 mm^(-1),andφ_(3)=-0.017 mm^(-1).Consi

关 键 词：光学设计 显微物镜 Buchdahl模型 平场复消色差 Micro-LED 

分 类 号：TH742[机械工程—光学工程]