CD characterization of nanostructures in SEM metrology
CD characterization of nanostructures in SEM metrology
复制标题
DOI：
10.1088/0957-0233/18/2/s26
复制
发表时间：
2007-02-01
影响因子：
2.4
通讯作者：
Dirscherl, Kai
中科院分区：
文献类型：
--
作者：
Frase, Carl Georg;Buhr, Egbert;Dirscherl, Kai
提出了一种由扫描电子显微镜(SEM)图像计算纳米结构临界尺寸(CD)的新算法。该算法基于扫描电子显微镜成像的物理模型，并对顶部和底部的CD进行评估。扫描电子显微镜的强度分布由分段定义的连续函数来建模，该函数通过最小二乘拟合的方法近似于从图像中提取的测量轮廓。该算法在一系列蒙特卡罗模拟中进行了测试，模拟的对象是边缘斜率角和电子探针直径的变化。模拟结果与模拟结果的最大偏差均小于3 nm。作为应用实例，给出了硅线结构的测量结果。
A new algorithm is presented that evaluates the critical dimension (CD) of nanostructures from scanning electron microscopy (SEM) images. The algorithm is based on the physical modelling of the SEM image formation and evaluates both top and bottom CDs. The SEM intensity profile is modelled by a piecewise-defined continuous function which is approximated to the measured profile extracted from images by means of a least-squares fit. The algorithm is tested in a series of Monte Carlo simulations with respect to a variation of the edge-slope angle and the electron probe diameter. The maximum deviation between the modelled and the simulated top and bottom CDs is smaller than 3 nm. As an application example, measurements of silicon line structures are presented.