The authors demonstrate the ability of scanning tunneling microscopy and spectroscopy to simultaneously measure the distributions of both the surface potential and the individual dopant atoms on the atomically flat hydrogen-terminated Si(111) surfaces prepared by an aqueous etching without disturbing the original dopant distribution. At the junctions, the acceptor and donor atoms were detected distinctly, and the variation in the observed height reflected the surface potential under the biasing condition. Further, a strong correlation between the dopant fluctuations and the surface potential distributions was identified.
We acquired curves at 32 points on each line with a length of , as shown in Fig. 2(a), and averaged them by excluding four curves that significantly deviated from the averaged one. The excluded curves were probably measured on an unhydrogenated dangling bond on the surface.
Averaging for the topography and the curves was performed on each of the parallel lines with a length of , which were similar to those shown in Fig. 2.