二维正交光栅结构的掠入射小角X射线散射测量  

Measurement of Two-Dimensional Orthogonal Gratings Using Grazing-Incidence Small-Angle X-Ray Scattering

作　　者：方彤 王成龙 喻虹[1,2,3] Fang Tong;Wang Chenglong;Yu Hong(Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Hangzhou Institute for Advanced Study,University of Chinese Academy of Sciences,Hangzhou 310024,Zhejiang,China;Zhangjiang Laboratory,Shanghai 201210,China)

机构地区：[1]中国科学院上海光学精密机械研究所,上海201800 [2]国科大杭州高等研究院,浙江杭州310024 [3]张江实验室,上海201210

出　　处：《光学学报》2024年第11期324-331,共8页Acta Optica Sinica

基　　金：张江实验室资助项目。

摘　　要：掠入射小角X射线散射(GISAXS)可进行光栅纳米结构的高分辨无损测量,有望应对半导体在未来节点的测量挑战。然而,传统的GISAXS方法主要用于线光栅的测量,对于二维正交光栅的测量缺乏较好的方案。本文提出了一种测量二维正交光栅结构关键尺寸的方法。建立了在任意入射角和旋转角下定位二维正交光栅布拉格峰的理论模型,基于此模型可以从GISAXS散射信号中提取样品倒易空间信息,从而实现三维结构重建。仿真结果表明,该方法可准确测量二维正交光栅纳米结构的立体轮廓,并显著减小所需的旋转扫描角度范围。这将为GISAXS在半导体测量中的应用奠定基础。Objective With the development of semiconductor technology,the critical dimensions of electronic devices in today’s integrated circuit manufacturing continue to shrink,and the devices are gradually transitioning from traditional planar transistor structures to complex three-dimensional(3D)architectures.While enhancing the performance of logic and memory chips,these changes also pose more measurement challenges.For instance,it is necessary to measure more structural parameters and smaller critical dimensions.Throughout the chip manufacturing process,it is crucial to conduct in-line measurements on the critical dimensions of various two-dimensional(2D)orthogonal grating structures to accurately characterize their structural shapes,thereby ensuring the processing quality.Grazing-incidence small-angle X-ray scattering(GISAXS)is a metrology technique capable of probing structural features on the order of 1‒100 nm and providing average topographic information over a large surface area.It enables high-resolution and nondestructive measurements and has the potential to address metrology challenges in semiconductor at future nodes.However,traditional GISAXS methods are mainly employed for measuring the critical dimensions of line gratings.When it comes to 2D orthogonal gratings,traditional GISAXS methods require the gratings to rotate gradually from 0°to 90°during measurement,which results in long measurement time.Therefore,there is still a lack of good solutions to 2D orthogonal grating measurement in GISAXS.Methods We propose a method to measure the critical dimensions of 2D orthogonal gratings with GISAXS.By analyzing the distribution of Bragg rods in the reciprocal space,a model for locating Bragg peaks of 2D orthogonal gratings at arbitrary incidence and rotation angles is built.Based on this model,the intensity of Bragg peaks can be accurately extracted and rapidly simulated,which helps obtain the reciprocal space information from GISAXS images at different rotation angles.To verify the validity of the propose

关 键 词：X射线光学 X射线散射 周期性纳米结构 关键尺寸 

分 类 号：O434.19[机械工程—光学工程]