电子束硅片图形检测系统中的纳米级对焦控制技术

郭杰; 李世光; 赵焱; 宗明成

doi:10.3788/CO.20191202.0242

Volume 12 Issue 2

Apr. 2019

Turn off MathJax

Article Contents

Chinese Optics > 2019 > 12(2): 242-255.

GUO Jie, LI Shi-guang, ZHAO Yan, ZONG Ming-cheng. Nano-scale focus control technology in electron beam wafer pattern inspection system[J]. Chinese Optics, 2019, 12(2): 242-255. doi: 10.3788/CO.20191202.0242

Citation:

GUO Jie, LI Shi-guang, ZHAO Yan, ZONG Ming-cheng. Nano-scale focus control technology in electron beam wafer pattern inspection system[J]. Chinese Optics, 2019, 12(2): 242-255. doi: 10.3788/CO.20191202.0242

Citation:

PDF( 4287 KB)

Nano-scale focus control technology in electron beam wafer pattern inspection system

doi: 10.3788/CO.20191202.0242

GUO Jie^{1, 2
,},
LI Shi-guang^{1, 2, 3
,
,},
ZHAO Yan³,
ZONG Ming-cheng^{1, 2}

1.
Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029, China
2.
University of Chinese Academy of Sciences, Beijing 100049, China
3.
Zhongke Jingyuan Electron(Beijing) Limited, Beijing 100076, China

Funds:

Program of Manufacturing Equipment and Complete Process of Very Large Scale Integration Circuits of China 2012ZX02701004

More Information

Corresponding author: LI Shi-guang, E-mail:lishiguang@tsinghua.org.cn
Received Date: 23 Apr 2018
Rev Recd Date: 04 May 2018
Publish Date: 01 Apr 2019

Abstract

Abstract

Charged particle beam imaging inspection technology is widely applied in semiconductor industry to find defects on wafers with nanometer degree measurement accuracy. During the wafer inspection, the wafer to be measured is supposed to be in the range of depth of focus(DoF) of the electron beam. In this paper we propose a close-loop wafer height control technology with millimeter range, nanometer accuracy and sub-microsecond height measurement time. It combines coarse control and fine control with an identical optical wafer height measurement system. During the coarse control, the imaging plane of the digital camera functions as a pure optical sensor. The wafer height information is obtained by measuring the displacement of one certain grating line. When approaching to the target position, the imaging plane changes to be a virtual digital grating. The so called optical vernier caliper, analogous with the mechanical vernier caliper, is constructed with the optical grating image and the digital grating image when there is some period difference between them. The experiment shows that such structure subdivides pixels by a factor of 10×or more on the image plane. When the system is used to measure the wafer height, the coarse measurement range is in millimeter degree and the coarse measurement time is 0.38 ms. The fine measurement resolution is less than 80 nm, and the fine measurement time is 0.09 ms. The close-loop feedback control is conducted with the system. The preliminary experiment shows the control accuracy is 15 nm. Such nanometer degree focus control accuracy is most advantageous in the charged particle beam inspection in the future.
- focus control,
- height measurement,
- height control,
- charged particle beam inspection,
- electron beam inspection,
- optical vernier caliper,
- depth of focus

FullText(HTML)

References(31)

References

[1]	CASS T R, HENDRICKS D, JAU J, et al.. Application of the SEMSpec electron-beam inspection system to in-process defect detection on semiconductor wafers[J]. Microelectronic Engineering, 1996, 30(1-4):567-570. doi: 10.1016/0167-9317(95)00311-8
[2]	OBERAI A, YUAN J S. Smart E-beam for defect identification & analysis in the nanoscale technology nodes:technical perspectives[J]. Electronics, 2017, 6(4):87. doi: 10.3390/electronics6040087
[3]	WILSON L. International technology roadmap for semiconductors-ITRS[R]. Washington: Semiconductor Industry Association, 2013.
[4]	MEISBURGER D, BRODIE A D, CHADWICK C, et al.. Electron beam inspection system and method: US, 5502306[P]. 1996-03-26.
[5]	WARD B W, NOTTE J A, FARKAS L S, et al.. Ion sources, systems and methods: US, 9236225[P]. 2016-01-12.
[6]	ZAFAR K, KEKARE S, CHANG E, et al.. Methods and systems for utilizing design data in combination with inspection data: US, 8923600[P]. 2014-12-30.
[7]	许志涛, 龙科慧, 刘金国, 等.空间相机调焦机构精度检测系统设计[J].液晶与显示, 2013, 28(6):943-947. http://d.old.wanfangdata.com.cn/Periodical/yjyxs201306024 XU ZH T, LONG K H, LIU J G, et al.. Design of focusing mechanism accuracy detection system of space camera[J]. Chinese Journal of Liquid Crystals and Displays, 2013, 28(6):943-947.(in Chinese) http://d.old.wanfangdata.com.cn/Periodical/yjyxs201306024
[8]	BLAIR W W, DORAN S K, LANGNER G O. Automatic focus and deflection correction in E-beam system using optical target height measurements: US, 4468565[P]. 1984-08-28.
[9]	COLLOPY T K, HAIRE D F. High resolution automatic focus correction electronic subsystem for E-beam lithography: US, 4821196[P]. 1989-04-11.
[10]	DORAN S K, ENICHEN W A, GROVES T R, et al.. Electron beam nano-metrology system: US, 5585629[P]. 1996-12-17.
[11]	王涛, 张涛, 张春光, 等.狭缝光栅分光特性及其对视区的影响[J].液晶与显示, 2013, 28(1):59-63. http://d.old.wanfangdata.com.cn/Periodical/yjyxs201301011 WANG T, ZHANG T, ZHANG CH G, et al.. Optical properties of parallax barrier and it's influence on view zone[J]. Chinese Journal of Liquid Crystals and Displays, 2013, 28(1):59-63.(in Chinese) http://d.old.wanfangdata.com.cn/Periodical/yjyxs201301011
[12]	WATANABE M, TAKEDA M, HAYAKAWA K, et al.. Charged particle beam apparatus and method for automatically correcting astigmatism and for height detection: US, 20060060781[P]. 2006-03-23.
[13]	SHIMIZU Y. Method for measuring resolution of charged particle beam and charged particle beam drawing apparatus: US, 20180040456[P]. 2018-02-18.
[14]	WANG J, NGUYEN V D, WANG Y X, et al.. Dynamic focus adjustment with optical height detection apparatus in electron beam system: US, 9400176[P]. 2016-07-26.
[15]	WANG Y X, NGUYEN V D, ZHANG J. Optical auto focusing system and methord for electron beam inspection tool: US, 20080302974[P]. 2008-12-11.
[16]	FABIJANSKA A. Subpixel edge detection in blurry and noisy images[J]. International Journal of Computer Science & Applications, 2015, 12(2):1-19.
[17]	GUIZAR-SICAIROS M, THURMAN S T, FIENUP J R. Efficient subpixel image registration algorithms[J]. Optics Letters, 2008, 33(2):156-158. http://d.old.wanfangdata.com.cn/NSTLQK/NSTL_QKJJ025592948/
[18]	ROSTYKU-SICAIROS M, ROSSI M, MOSER C. Compact lensless subpixel resolution large field of view microscope[J]. Optics Letters, 2018, 43(8):1654-1657. doi: 10.1364/OL.43.001654
[19]	陈晓东, 李为民, 李静, 等.利用重心法求光斑信号位置的误差分析[J].光学技术, 2000, 26(1):5-8. doi: 10.3321/j.issn:1002-1582.2000.01.005 CHEN X D, LI W M, LI J, et al.. Error analysis of the center of gravity method when used to get the position of a facula[J]. Optical Technique, 2000, 26(1):5-8.(in Chinese) doi: 10.3321/j.issn:1002-1582.2000.01.005
[20]	李朝辉, 武克用.图像矩心内插法在空间相机实时检焦中的应用[J].光学精密工程, 2000, 8(4):335-339. doi: 10.3321/j.issn:1004-924X.2000.04.008 LI CH H, WU K Y. Application of centroid sensing method in real-time autofocusing system used in space camera[J]. Opt. Precision Eng., 2000, 8(4):335-339.(in Chinese). doi: 10.3321/j.issn:1004-924X.2000.04.008
[21]	谢伦治, 卞洪林, 王振华.面阵探测器的像点亚像素定位研究[J].光学与光电技术, 2003, 1(2):51-56. doi: 10.3969/j.issn.1672-3392.2003.02.014 XIE L ZH, BIAN H L, WANG ZH H. Study of the subpixel interpolation of image spots with matrix detectors[J]. Optics & Optoelectronic Technology, 2003, 1(2):51-56.(in Chinese) doi: 10.3969/j.issn.1672-3392.2003.02.014
[22]	王海涌, 黄江艳.CCD视频幅值调节器的设计及目标精确定位算法[J].光学精密工程, 2008, 16(6):1105-1109. doi: 10.3321/j.issn:1004-924X.2008.06.022 WANG H Y, HUANG J Y. Design of CCD video amplitude controller and target precise locating algorithm[J]. Opt. Precision Eng., 2008, 16(6):1105-1109.(in Chinese) doi: 10.3321/j.issn:1004-924X.2008.06.022
[23]	王林波, 王延杰, 邸男, 等.基于几何特征的圆形标志点亚像素中心定位[J].液晶与显示, 2014, 29(6):1003-1009. http://d.old.wanfangdata.com.cn/Periodical/yjyxs201406024 WANG L B, WANG Y J, DI N, et al.. Subpixel location of circle target center based on geometric features[J]. Chinese Journal of Liquid Crystals and Displays, 2014, 29(6):1003-1009.(in Chinese) http://d.old.wanfangdata.com.cn/Periodical/yjyxs201406024
[24]	BOONMAN M E J, BROODBAKKER P J M, NIJMEIJER G J, et al.. Off-axis levelling in lithographic projection apparatus: US, 20040130691[P]. 2004-07-08.
[25]	HIDAKA Y, NAGAYAMA T. Surface position detection apparatus, exposure apparatus, and exposure method: US, 9927713[P]. 2018-03-27.
[26]	DENBOEF A J. Optical wafer metrology sensors for process-robust CD and overlay control in semiconductor device manufacturing[J]. Surface Topography:Metrology and Properties, 2016, 4(2):023001. doi: 10.1088/2051-672X/4/2/023001
[27]	节德刚, 刘延杰, 孙立宁, 等.基于双光栅尺的高速高精度位移测量方法[J].光学精密工程, 2007, 15(7):1077-1083. doi: 10.3321/j.issn:1004-924X.2007.07.014 JIE D G, LIU Y J, SUN L N, et al.. A high speed and high precision displacement measurement methord using double grating scales[J]. Opt. Precision Eng., 2007, 15(7):1077-1083.(in Chinese) doi: 10.3321/j.issn:1004-924X.2007.07.014
[28]	吴耀春, 萧泽新.基于光栅检测的显微镜闭环扫描控制系统的设计[J].光学与光电技术, 2008, 6(2):71-73, 77. doi: 10.3969/j.issn.1672-3392.2008.02.019 WU Y CH, XIAO Z X. Design of microscopical closed-loop scanning and control system based on grating checks[J]. Optics & Optoelectronic Technology, 2008, 6(2):71-73, 77.(in Chinese) doi: 10.3969/j.issn.1672-3392.2008.02.019
[29]	RAKHMANOV M, EVANS M, YAMAMOTO H. An optical vernier technique for in situ measurement of the length of long Fabry-Perot cavities[J]. Measurement Science and Technology, 1999, 10(3):190-194. doi: 10.1088/0957-0233/10/3/013
[30]	CHEN F F, FENG J, HONG ZH W. Digital sun sensor based on the optical vernier measuring principle[J]. Measurement Science and Technology, 2006, 17(9):2494-2498. doi: 10.1088/0957-0233/17/9/017
[31]	赵斌.环栅图像的数字莫尔条纹扫描定中方法[J].光学精密工程, 2002, 10(1):19-24. doi: 10.3321/j.issn:1004-924X.2002.01.004 ZHAO B. Digital moire fringe scanning method for centering ring grating images[J]. Opt. Precision Eng., 2002, 10(1):19-24.(in Chinese). doi: 10.3321/j.issn:1004-924X.2002.01.004