摘要
设计了大面积循环扫描投影光刻的高精度对准系统,由CCD传感器、图像识别软件和共焦显微镜组成的光学测量系统和对掩模和基片的相对位置作二维和角度及时修正的精密定位系统两部分组成。标记图像的二维方向扫描分别借助光刻平台的移动和振镜的高频振动来完成。理论分析了标记位矢对准、共焦成像和CCD信号相关双采样关键技术。根据掩模和基片对应位矢的夹角余弦值大小控制基片的旋转和平动,对准更方便快捷;由共焦成像系统二维响应函数的推算,针孔滤波对提高成像分辨率很重要;对CCD像元电荷包实时准确地采样,是排除噪声干扰的关键。
A high-precision alignment system for a large-area scan-and-repeat projection lithography is designed. It consists of an optical metrology system including confocal scan microscope, CCD, pattern recognition and a fine positioning system used for a relative two dimension and angle correction in the position of the substrate with respect to the mask. The scan to a mark image in two dimensions is done by the planar stage to move and the vibration mirror to vibrate in a high frequency respectively. Meanwhile, the key technologies about the alignment of mark displacement vector, the confocal image and the correlated couple sampling of CCD output signal are analyzed theoretically. The alignment is more convenient and quick by angle cosine value of the corresponding displacement vectors to control the turn and movement of the substrate. Pinhole filter is important to raise image resolution by deducing the response function in two dimensions of the confocal image system. The sampling timely and exactly for CCD pixel charge packet is the key to get rid of the noise interference.
出处
《半导体光电》
CAS
CSCD
北大核心
2009年第3期455-459,共5页
Semiconductor Optoelectronics
基金
广东省自然科学基金项目(07001789)
广东省科技计划项目(2007B010400071)
关键词
投影光刻
对准
激光共焦扫描显微镜
CCD相关双采样
projection lithography
alignment
laser confocal scan microscope
CCD correlated eouple sampling
