基于纳米针尖反射靶的X射线显微系统
宋 健1，2，牛 耕1，刘俊标1*，赵伟霞1，马玉田1，韩 立1
（1.中国科学院电工研究所，北京100190；2.中国科学院大学，北京100049）
摘 要 本文利用电化学腐蚀方法制备出曲率半径＜100 nm的钨针尖，并在FEI Quantum 600型扫描电镜(SEM)中作为反射靶材以搭建微焦点X射线显微系统。通过SEM发射电子束轰击纳米钨针尖，以减少电子束和靶材的物理作用区域，进而减小X射线源的光斑尺寸，实现高分辨率的X射线显微成像。采用线对卡来评价系统的最佳成像分辨率，实验结果表明：系统在加速电压30 kV、电子束束流120 nA、SEM的工作距离5 mm、放大倍数为100倍、探测器采集时间为180s的条件下，可以获得优于1μm的分辨率图像。
关键词 纳米针尖制备；低能X射线显微技术；无损检测；电化学腐蚀法
中图分类号：TG115.22；TG115.21+5.3 文献标识码：A doi:10.3969/j.issn.1000-6281.2016.04.002
X-ray microscope system based on nano-tip reflection targets
SONG Jian1，NIU Geng1，LIU Jun-biao1*，ZHAO Wei-xia1，MA Yu-tian1，HAN Li1
（1. Institute of Electrical Engineering，Chinese Academy of Sciences，Beijing 100190；
2. University of Chinese Academy of Sciences, Beijing 100049）
Abstract In this paper, tungsten tips with tip curvature radius less than 100 nm were fabricated by electrochemical etching method, which were used as the reflection target to build the X-ray micro-imaging system. The reaction region of the electron beam and the target could be reduced by bombarding the tungsten tip with electron beam，so as to minimize the spot size of the X-ray source and achieve high resolution X-ray micro-imaging. The line-pair-card was used to evaluate the best resolution of the system. Experimental results showed that the SEM images with resolution better than 1μm could be obtained at the confined conditions, of which the acceleration voltage was 30 kV，the electron beam current was 120 nA，the working distance was 5 mm, the magnification was 100 times and the detector acquisition time was 180 s.
Keywords nano tip fabrication；low energy X-ray micrography technology；nondestructive testing；electrochemical etching method
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[1] 陈洁, 柳龙华, 刘刚, 等. 高分辨率X射线显微成像及其进展[J]. 物理，2007，36（8）：588-594.
[2] 李光, 罗守华, 顾宁. Nano CT成像进展[J]. 科学通报，2013，58（7）：501-509.
[3] 张朝宗，郭志平，张朋，等. 工业CT技术和原理[M]. 北京：科学出版社，2009: 88-180.
[4] STAHLHUT P, EBENSPERGER T, ZABLER S, et al. A laboratory X-ray microscopy setup using a field emission electron source and micro-structured reflection targets[J].Nuclear Instruments and Methods in Physics Research B，2014，324：4–10.
[5] BRYANT P J, KIM H S, ZHENG Y C, et al. Technique for shaping scanning tunneling microscope tips [J]. Review of Scientific Instruments，1987，58（6）：1115-1115.
[6] KIM Y G，CHOI E H，KANG S O，et al. Computer-controlled fabrication of ultra-sharp tungsten tips[J]. Journal of Vacuum Science & Technology B，1998，16（4）：2079-2081.
[7] ANWEI L, XIAOTANG H, WENHUI L, et al. An improved control technique for the electrochemical fabrication of scanning tunneling microscopy microtips[J]. Review of scientific instruments, 1997, 68(10): 3811-3813.
[8] IBE J P, BEY JR P P, BRANDOW S L, et al. On the electrochemical etching of tips for scanning tunneling microscopy[J]. Journal of Vacuum Science & Technology A，1990，8（4）：3570-3575.
[9] HOBARA R, YOSHIMOTO S, HASEGAWA S, et al. Dynamic electrochemical-etching technique for tungsten tips suitable for multi-tip scanning tunneling microscopes[J]. e-Journal of Surface Science and Nanotechnology. 2007，5：94-98.
[10] KHAN Y, AL-FALIH H, ZHANG Y, et al. Two-step controllable electrochemical etching of tungsten scanning probe microscopy tips[J]. Review of Scientific Instruments，2012，83：063708 .
[11] 刘平, 姚琲. 扫描隧道探针的制备研究[J]. 现代仪器, 2003 （6）: 30-32.
[12] 胡小唐, 郭育, 刘安伟, 等. 微探针电化学加工机理及针尖尺寸控制技术[J]. 化工学报，1995，46（5）：557-561.
[13] 臧侃, 侯宾宾, 游燕, 等. 利用优化差分电路制作扫描隧道显微镜针尖[J]. 电子显微学报，2016，35（1）：9-16.
[14] 臧侃, 侯宾宾, 孙雨雪, 等. 一种新型扫描隧道显微镜针尖腐蚀仪的设计[J]. 电子显微学报，2015，34（2）：111-120.
[15] JU B F, CHEN Y L, GE Y. The art of electrochemical etching for preparing tungsten probes with controllable tip profile and characteristic parameters[J]. Review of Scientific Instruments，2011，82：013707.
