用于晶圆键合的对准标记定位算法  

A high-precision positioning algorithm of alignment mark for wafer bonding

作　　者：鲁沛昕 杨开明[1,2] 鲁森 朱煜[1,2] Lu Peixin;Yang Kaiming;Lu Sen;Zhu Yu(Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China;State Key Laboratory of Tribology,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学机械工程系,北京100084 [2]清华大学摩擦学国家重点实验室,北京100084

出　　处：《仪器仪表学报》2021年第11期220-229,共10页Chinese Journal of Scientific Instrument

基　　金：摩檫学国家重点实验室基金(SKLT2020D23)项目资助。

摘　　要：对准标记精确定位是晶圆键合精度实现的关键,为了提高对准标记定位算法的精度、实时性及适应性,提出了一种基于边缘检测拟合定位的高精度对准标记定位算法。该方法结合分级金字塔模型对对准标记进行逐级定位,获得像素级的目标区域粗定位结果,根据目标区域粗定位结果,结合Canny检测器与改进的高斯拟合法,对对准标记的亚像素轮廓进行拟合,在此基础上结合中心对称的对准标记特征,利用改进后的最小二乘法快速拟合对准标记的中心位置,实现对准标记的精确定位。通过实验验证了该方法的有效性,实验结果表明,提出的对准标记定位算法在快速定位目标区域的同时,可实现约0.06μm的重复定位误差,满足了晶圆键合对准的精度、实时性和适应性的需求。The accurate positioning of the alignment mark is key to wafer bonding accuracy.To improve the accuracy,speed and adaptability of the alignment mark positioning algorithm,a high-precision alignment mark positioning algorithm based on edge detection and fitting positioning is proposed.The method combines the hierarchical pyramid model to locate the alignment mark stepwise,and achieve the pixel-level coarse positioning result of the target area.According to the coarse positioning result of the target area,the method combines the Canny detector and the improved Gaussian fitting method.In this way,the sub-pixel contour of the alignment mark is fitted.On this basis,the center position of alignment mark is quickly fitted by the center symmetrical alignment mark feature and the improved least square method to realize accurate positioning of the alignment mark.The effectiveness of the method is evaluated through experiments.Results show that the proposed alignment mark positioning algorithm can locate the target area quickly while the repeat positioning error is about 0.06μm,which satisfies the requirements of wafer bonding alignment in terms of accuracy,speed and adaptability.

关 键 词：晶圆键合对准 对准标记定位 高精度 亚像素 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术] TH822[自动化与计算机技术—计算机科学与技术]