基于纳米针尖反射靶的X射线显微系统

X-ray microscope system based on nano-tip reflection targets

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 k V、电子束束流120 n A、SEM的工作距离5 mm、放大倍数为100倍、探测器采集时间为180 s的条件下,可以获得优于1μm的分辨率图像。

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 1 μm 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.