中国激光, 2014, 41 (10): 1008001, 网络出版: 2014-08-15
差动共焦显微边缘轮廓检测与定位方法
Differential Confocal Microscopy for Edge Contour Detection and Location
测量 边缘检测与定位 差动共焦显微术 过零触发 微结构检测 measurement edge detection and location differential confocal microscopy zero-crossing trigger microstructure inspection
摘要
为了实现高效、准确的检测和定位微结构如光刻掩模版的边缘轮廓,提出了一种差动共焦显微(DCM)边缘轮廓检测方法,并对该方法进行了原理仿真分析和实验验证。该方法具有在焦点的过零阶跃触发特性。利用该特性,该方法可以实时得到样品二值化边缘轮廓图像,极大地提高了边缘轮廓检测效率。理论分析和仿真表明,该方法边缘定位准确,不受边缘形状、方向和样品有效反射率的影响,可以有效抑制噪声和干扰。5 μm周期台阶标准样品周期测量对比实验表明,该方法所得边缘轮廓能够实现高精度的横向尺寸测量,因此能够用于微结构的快速工业边缘轮廓成像检测。
Abstract
In order to realize high-efficiency and high-accuracy edge contours detection and location for micro structures such as photolithographic mask, a differential confocal microscopy (DCM) for edge contour detection and location is proposed and verified by simulation analysis and experiments. The proposed method has an axial response characteristic of zero-cross step trigger at focal point. Utilizing the step trigger characteristic, the proposed method can realize the real-time sample edge contour imaging in the form of binary image, and greatly improve the efficiency of edge contour detection. Theoretical analysis and computer simulations show that the proposed method can precisely detect and locate the edge contour without being affected by edge shape and direction, and has the ability of suppressing the interference caused by multiplicative and additive noise. Experimental results indicate that period measurement difference of 5 μm-period atomic force microscope standard step between the proposed method and atomic force microscope is only 2 nm. So the proposed method can be used for the real time, precise and rapid industrial edge contour inspection for microstructures.
刘大礼, 王允, 邱丽荣, 赵维谦. 差动共焦显微边缘轮廓检测与定位方法[J]. 中国激光, 2014, 41(10): 1008001. Liu Dali, Wang Yun, Qiu Lirong, Zhao Weiqian. Differential Confocal Microscopy for Edge Contour Detection and Location[J]. Chinese Journal of Lasers, 2014, 41(10): 1008001.