Journal of Vacuum Science & Technology B, Vol.26, No.6, 2069-2072, 2008
Multilevel visualization of local electric field at probe apex using scanning electron microscopy
The authors have found that the locally enhanced field at a probe apex can be visualized using conventional scanning electron microscopy (SEM) under a low accelerating voltage. The local electric field deflects the primary electrons in the vicinity of the apex. They placed a gold grid detector just beside the beam axis to detect these deflected primary electrons. The secondary electrons thus generated from the grid simultaneously created a concentric contour ring around the probe apex in the SEM image. Thus, a simple Rutherford scattering model could be adopted to analyze the local electric field distribution at the tip apex.